One look at my profile pic and you can probably already tell how I feel about this part without even needing to look at my review scrore. However, I should probably elaborate on my opinion anyway (I would have just left it at that, but myanimelist wouldn't let me right such a small review).
When I first began reading the jojo's bizarre adventure manga series, I would occasianlly see a sailor character in the line up of the JoJo's who appear throughout the series and the first time I saw this JoJo I feel in love. It was both a mix of araki's beautiful part 7/8 art style and the saillor outfit that gave him such a unique look that made me have have such an infatuation with this character. though I was only on phantom blood at the time, I wanted to speed through the rest of the parts just to meet this JoJo that the fans had dubbed "gappy".
This took me a while (about a year and a half to be exact) but when I got there, after the dissapointing, but still well written steel ball run, I began to read chapter after chapter of this work until I got all caught up. Now that's enough back story, onto the actual review.
Art
I have always loved Hirohiko Araki's art style, the amount of detail and work that has gone into some of his panels is truly astounding and always left me wondering how he kept up a weekly schedule with such beautiful art. Though I thought his art was great while he still published in weekly shonen jump, his move to a monthly seinen magazine and an art style evolution somehow improved on it's beauty.
Story
The story of this part is quite different than the other parts in the sense that it is a mystery story where we know next to nothing about the JoJo from the beginning of the series and don't learn a lot until quite a few chapters later and information is slowly drip fed to the reader throughout the chapter, makign the reader want to read on impulsively just to know more about what's going on. Oh, and its set in morioh, that same place from diamond is unbreakable and it was really fun seein all these new characters being mirrors of those from past parts.
Characters
As this is JoJo's bizarre adventure you can expect the characters to be both well written and, of course, bizarre and araki doesn't dissapoint, offering up a wide variety of interesting people to meet in this new morioh town. Such as, the higashikata family who's members each have their own distint bizarre personality (joshu being my favourite0 or gappy himself who's amnesiac trait gets him into some hilarious and bizarre situations.
What I love about both this part and the previous one, sttel ball run, is that nearly every character is morally grey, rarely do you find a character who is doing evil just for the sake of it *cough*DIO*cough* or any character who can be seen as the perfect hero. Araki's writing is at a master level in these last two parts.
What I didn't like
Now, from all the praise I have given this , you probably think I would have hardly any complaints...and you would be right! However, I do have one complaint which is probably the only thing I think araki could improve on in this point in his career and that is his forgetfullness. There are a few moments throughout the whole JoJo's bizarre adventure series where I have thought "wait, what happened to *insert cool/mysterious thing that never shows up again or never ends up getting explained*?" and this part is not free from those moments but there were fewer than past parts which helped.
In summary: part 9 will have to try really hard to top jojolion and steel ball run has nothing on this masterpiece...