Some people love this part, and of course they have every right to, but I just don't get it. This part has zero appeal, the story is boring and beside the usual weirdness it doesn't feel like JoJo at all.
This review is being written while chapter 94 is out and we are in a hiatus, so I might update it or write another when the series end.

Story: Pointless (1/10)
The climax of this part is people waiting fruits to grow. You never know what this part is about, and fans talk like it's the best thing ever, but do you really enjoy reading a story that goes nowhere for years? Most fights are boring and feel to take forever to end, and it's one of the reasons why it's so hard to read this part, since this is a battle-seinen manga. The only good ones were Vitamin C and Ozon Baby that I remember. The worst is obviously the beetle fight arc, that people enthuse about and say it's one of the best, but I guess it's just a meme, like some people ironically like the movie "The Room".
Talking about fights, Soft & Wet is one of the worst stands we have for a Jojo. Its design is awful and shows zero personality (I guess it suits well its user, then) and it's so overpowered that he can pull anything out of his ass during fights and bullshit his way to victory. Remember in the beginning when it took Joshu's eyesight and then he never used that trick again? Well, it got to be nerfed at least a little, otherwise all fights would last like 10 seconds. Not that being stupid is something exclusive for Soft & Wet, since most stands here are either useless or overpowered, the worst case of this being Paper Moon King. Still, there are a few decent ones like Speed King and King Nothing, but they are very rare.

The only thing that sticks you to the story is the mistery about Josuke's identity. You hype for it to be something big, when it actually is so stupid and unnecessary that it could be brought in the first chapters. Because he already knew he was Kira since the beginning and the part that was missing was Josefumi, who is also a boring and uninteresting character who adds nothing to the plot. Still, it was dragged on and overhyped as something important, but nothing changed. After Josuke recognizing his identity he often states that he is a fusion, but in practice he is just Kira. Norisuke adopted him because he is Kira. The damokan were after him because of Kira. He meets Kira's sister, and is doing a giant effort to help Kira's mother, while he didn't even think about researching Josefumi's life or caring if he has a family who is missing him.

After that, the plot starts revolving around the rokakaka fruit, which might be the worst artifact in the series. Compare it to the stone mask: It could transform you into a vampire and it was made by pillar men, later Kars used it with the stone of aja to achieve his goal. Now, this dumb fruit: It can bring you something you want but you have to give away something in return, it could end there but they introduced the New Rokakaka and didn't give us a clue what that was about and later the Locacaca 6251, and again nothing about it. We don't know what it does and why is it so OP.

Anyways, having the plot of this part being about fruits is ridiculous. The previous ones had amazing ideas, like finding pieces of a holy corpse that could give you powers, trying to stop the end of the universe, searching for a serial killer blended in a small town, and so it goes. I have my own opinion about them as well, for example I dislike part 5 more than part 8 for various reasons, but fighting gangsters to become the boss of the mob seems like a way better story than collecting fruits.

Art: Mostly ok (6/10)
Araki has improved his art skills throught the years and part 8 have some of the most detailed shots. But since the story is based in the same town, we don't see anything out of the normal being drawn.
Yet, the character design is dull. Yasuho's is gorgeous, but the rest is boring, like Josuke's sailor outfit. Some others like Josefumi, Tsurugi and Joshu are just awful and bad looking.

Character: (1/10)
This part also has some of the worst characters in all of the series, and I eventually will get to it.
Let's talk about the protagonist, Jo2uke. His personality is totally flat and has almost nothing likeable. In 94 chapters we know nothing about his own goals or motivations, and the only time he shows any characterization is when he helps his/ Kira's mother. He is the total opposite of the original Josuke.
Yoshikage "K2ra", as the name says, is this universe's version of DiU's main villain. Yet he doesn't look anything like Kira besides the name, has nothing of the original Kira's coolness and is just boring as Jo2uke. People love to say he is the SBR version of Jotaro, but he also has zero similarities with him, and so is his sister Kyo Nijimura.
By the surname, you could say Kyo is this universe version of Okuyasu, but besides looking like a JoBro in the first chapters, being the one to reveal Josuke's identity, she vanishes and does nothing for the rest of the part. I mean, HER BROTHER whom she says to care about is in a certain way alive and is the protagonist of this part, looking for a way to defeat the rokakaka organization and save their mother, but she rather clean the Higashikata house than help him?
Some characters we get to know are recurring, but they don't take any part in the story besides always showing up. Like the Higashikata sisters, Daiya and Hato.

What we see is Joshu, a character people see as meme when he shouldn't exist. He is abusive, disgusting and literally tried to rape Yasuho. And after that he gets his own arc and gets to do a lot of other shit during this part. I mean, what the hell Araki?
Not that molesting Yasuho is only his thing. Wu Tomoki also did it, and also Tsurugi. Jobin's child competes with Joshu for who is the worst character of the part. After the retcon that change his age from 2 to 10-11, this kid has been nothing but nuisance. The entire plot revolves about getting those fruits to him so he could heal his sickness. Everyone feels they need to help him, and not only his family, but also Josuke and Yasuho. And how does he retribute? Like I said before, molesting Yasuho, trapping her in a nightmare world, and also bringing enemies to the protagonists. His stand is ridiculous and no one can explain how it works, so he basically can teleport people from a point to another, fake his and his father's death and instant kill people around him. There is no fight, he just does whatever he wants and that's it. That's a main villain's stand right there, and it belongs to an annoying child we are supposed to care about.

The only good characters in this part are Mamezuku, Norisuke, Yasuho and possibly the Head Doctor.
Norisuke also suffered a retcon. He wanted to kill Josuke, but then became his ally. What happened to that? That apart, he is one of my favorites and one of the few characters in this part that aren't annoying, and the only one worth of something in his dumpster fire family that we are forcedly supposed to care about. Too bad, because I really like Hato and her development, she was a badass when defeating Tamaki Damo after being used by him. Yet, she suffers the Kyo Nijimura treatment and is forgotten for the rest of the part.
About Mamezuku, I can say for sure that he is the best character of this part. He gives a classic JoBro vibe (besides Yasuho being the main JoBro here), has a cool stand that is interesting to see in fights and does a good trio with Josuke and Yasuho. His late introduction is something disappointing, as he only first appears in chapter 65, I mean, we never had a major ally introduced after almost 3/4 of the part before! Imagine if he had appeared earlier and sticked with Josuke for the rest of the part, if the second fight was against him and not useless Daiya, and if it was him to help Josuke in Shakedown Road and in EoH instead of fucking Joshu? Anyway, at least his character was created.
And Yasuho, maybe the most mistreated character in this part. Can't say she wasn't annoying in the beginning, because she was. In one day after meeting the protagonist she is already in love with him. Their relation is forced and I can't take it seriously, nor ship it. I mean, by the second time they meet in their life, they are crying as they were super close friends who don't see each other in years.
Besides being a submissive light-headed waifu to Josuke, she is a cool character later in the part, as we know more about her and she shows her skills. She becomes a great character and deserved to be in a better part than this one, maybe in Koichi's place in part 4.

One of the main discussions about the characters is which one of them will be the main villain, as we are reaching the end and it still hasn't been revealed. The most obvious choice is Jobin because of his power, his relevance and the focus he gets in the chapters. But yeah, there are other plotlines, like Kaato, who shows up as a villain and does nothing besides taking sunbaths on the garden. She couldn't do much tho, as her stand is just a bad version of Enigma, one of part 4's best stands. There is also the Head Doctor, that has been focused for the last 15 chapters and we still hasn't resolved it and it doesn't look like it's going to be the final fight.

Enjoyment (1/10)
I think I already defined it. Jojolion has a boring story that goes nowhere, almost all of the characters are annoying and the fights are mostly running away from something until the enemy gets defeated. You can get enjoyment from this as a lot of people on these reviews do, but I didn't manage to do it.
For me the best part of Jojolion was the flashback of Johnny Joestar and Rina Higashikata. Not only because I love Johnny, but it also gave this part more context and connection with the previous one.

Overall (1,5/10)
If it isn't the worst part of JoJo, it's surely one of them. I personally hated part 5 and 6 more, but because of the frustration I got from them in the second half and in the end, respectively. With part 8, it's.... just boring from the beginning.
Jojolion got better when Mamezuku first appeared to form the main trio, and you could skip the beginning and start there, because nothing happens.
I got really hyped with the Head Doctor arc. It made Jojolion interesting. But now what happened? A lot of chapters later, Josuke still hasn't reached him and the plot is going somewhere else.
As I write, we are in a cliffhanger where Yasuho got crippled and probably died in the stupidest way possible. You could have Jobin punch her with his stand and burn her to death, instead he damages a phone Paisley Park is in, by throwing it in a toilet. That's it, the JoBro of this part dies like a joke. We came from Caesar's epic fight with Wammu in part 2 to this, a main character dying in a toilet because she was searching for a fruit.

I don't know what happened to JoJo. All parts have their flaws, but this part itself is a flaw. Part 7 was amazing and one of the best of the series, so I don't understand what happened to Araki when he decided to do this one. I guess he should end Jojolion as soon as possible and forget this part even existed, so if a part 9 happens it may be better.

EDIT Chapter 100: I did a more complete review of Jojolion in a video, if anyone is interested: https://youtu.be/HBLqg8so0Uw