JoJo's is bizarre. I believe that any reviewer worth his pixels should summarize their opinions on the previous parts before they start their review, since these opinions are integral to the reader's understanding. So, that being said:
Part 1: A bit boring, but does a good job at establishing the JoJo vs Brando rivalry. The quintessential hero JoJo.
Part 2: Best part I've seen so far. The Pillar Men are good antagonists and Joseph is the best protagonist. The quintessential anti-hero JoJo.
Part 3: [CONTROVERSIAL OPINION ALERT] Worst part I've seen so far. Would take too long to explain, if you're interested, PM. Basically, very overrated, but good JoJo.
[Onto Part 4]
So, how does part 4 stack up? Well, I personally think that this is the second best JoJo part so far. It, in many ways, fixes the problems that I had with part 3. The sense of scale has been drastically decreased. I mean, seriously decreased. Fans went from a globe-spanning battle for humanity against DIO to a battle for a quaint little town against a serial killer with a hand fetish. This makes each battle seem more individually meaningful. The characters are (arguably) better as well. Unfortunately, none of the OPs stood out as amazing (sonically, I mean). Obviously, the visuals were amazing throughout the entire show- because JoJo's.
Overall, I'm very satisfied with this part. It wasn't perfect, but it was a good season and I really enjoyed it. 9/10