While Part 3's anime adaptation is my least favorite anime from JoJo franchise, I was pretty much skeptical about reading Part 3 manga, although many people encouraged me to do read it, since it fixed a lot of things that I found annoying in Part 3's anime adaptation. And they were right.
Jotaro is really likeable character with his own specific personality (he is not that expressive like Joseph, but he's a good guy); the pacing is way, way better; fights are more interesting and more dynamic.
I'm not saying that Part 3's anime was bad. It was good in its own way, expanding the source material by a lot of things that served their purpose as additional content. I just didn't like it. It was too long, too slow and did not make a good transition from Hamon to Stands. Unlike the manga.
I really liked this manga. Very good one, filled with great action, likeable characters, a lot of humor and bizarre situations. In fact, at least when it comes to JoJo manga, Stardust Crusaders became one of my favorite JoJo mangas. ;-)