For me and I can only speak for myself, it is the characters that really make me think the PT movies are OK instead of great. I just can't grasp to any of the characters other then ObiWan in someways, but Anakin & Padme are the key to the trilogy, you have to care about them, their fate, their tragedy.
For me, I watch the PT movies and enjoy the story cause it ties into the OT, but they just don't hit on an emotional level that the OT does, and that is cause of the characters, and I think that is the dirty little secret that everyone misses.
I think ROTJ is a good sequel, but not as great as ANH/ESB, but I love it just as much, cause of those characters that Lucas developed. Lucas could have made 7,8,9 of Fisher, Ford, and Hamill with the same quality as ROTJ and I think I would have still loved the movies, that is the power of characters in movies for me personally.
The PT was going to be tough cause it has to introduce new characters or younger characters from the OT movies, but they were all DIFFERENT ACTORS, and that is huge for a new set of movies to be tied into ones that have utterly lovable characters. And it has nothing to do with the fact that they are not the ultimate good guy characters, cause the PT was not going to be that type of trilogy.
But I don't know how you could convince me that I am wrong about the PT movies, when I have zero attachment to Anakin/Padme for 3 movies, cause I just feel you have to care about the characters, and then the director has the viewer for 2 hours.
Characters, I still believe it is the biggest failure of the PT, and everyone has an opinion: Do I care about these characters or not?