After reading part 3, which I personally didn't like at all, my patience was rewarded with one of my favorite parts of Jojo, and one of the best mangas in general.

My biggest problems with Stardust Crusaders are the flat characters, poor pacing, and the so-so stands. Diamond is Unbreakable shatters those weaknesses. While only two or three characters really go through any real, continuous arc, I enjoy all of them here, and they have clear personalities. While I don't like Yoshikage Kira as much as others, he's a great villain, and the minor villains are alright too. Jotaro feels more natural as the mentor who shows up on occasion. Okuyasu is an idiot, but he's my idiot. Koichi is a great character that sometimes feels more like the protagonist than our new Jojo. Josuke, our new protagonist, is goofy and fun, but he still feels like I normal kid, and part of the fun is seeing him learn to use his stand in great ways.

And what a stand he has. Stands are much more creative here than in part 3. The more limited and specific stands allow for battles that are creative and exciting. There are many more unique battles than before as well. The Darby fights were the only ones in part 3 that felt truly different, but the Italian food arc of Part 4 is much different than the Love Deluxe arc, which is different than the Highway star arc, and so on.

Now, what about the pacing? Well, this is actually much longer than part 3, but this slow pace works better here. Part 3 is supposed to be climactic and there's a ticking time bomb, so the unnecessary fights feel that much more unnecessary. In part 4, the scale is much smaller, and the story is almost slice-of-life. This is a surprisingly excellent genre blend. For many, the main villain not appearing until several volumes in may feel wrong, but it helps the tone of the story in my opinion. If we knew about Kira from the beginning, we'd never appreciate the slower moments.

Another thing is that overall, Part 4... makes more sense than the other parts. As much as a like Jojo, there's a decent amount of insanity, deus ex machina, plot holes, and contrivances. However, this is rarely in Diamond is Unbreakable. There is still the occasional lack of narrative tightness, but regardless, it never affects my enjoyment.

One other thing, the art is... amazing. This is some of the best weekly art I've ever seen. It does change from Araki's more masculine and edged style to the soft, somewhat feminine style that Araki is still developing today, but it looks good regardless, and the change is subtle enough that it doesn't take me out. Another thing is that sometimes when minor villains are defeated, they get shorter once they become 'good guys', which I like as an idea, but the first time I saw it I thought, 'who is this'? It was very odd and confusing, but since I pointed it out to you, you'll be fine reading it. (These characters are also short from the beginning in the anime, and the artstyle is also completely consistent throughout.)

You should read this. Should you read it as a standalone story and skip 1-3? You could watch a recap of the previous parts and then read this, but I don't recommend it. Reading all of Jojo is more satisfying anyway. I haven't watched much of the anime, but it seems to be a good adaptation that is more consistent with art, as I said before.