It really should be ANH and ESB vs. ROTJ and the PT. That would be a more apt and accurate distinction.
I'd be game for that honestly.
While I don't view ROTJ as bad as the prequels, it's not without its faults. The Luke/Leia sibling crap felt forced, the character exchanges were strange, Ewoks, etc. The ending celebration is kind of weird too.
We're all talking about caring for characters but, Han Solo seems REALLY different in ROTJ, almost unlikable. The character we saw in Star Wars and Empire is nonexistent in ROTJ but of course we're reminded, "hey, it's me". No it's not. Where the character should be thankful that he's alive we get a bitter fool that seems to be annoyed by everything.
In fact, all the characters except maybe Luke seem like larger caricatures of what they were in the previous films. Luke is the only one that really evolves, while the others are just one-dimensional.
However, let me reiterate that they aren't PREQUEL bad. Things like the beginning with Jabba's palace, meeting the Emperor and the final confrontation with Darth Vader is fantastic stuff. The father/son thing pays of as does Vader's choice to end the Emperor. That whole sequence is fantastic.
But, it's not as strong as SW and Empire and that's what makes it weak. It also suffers from a few writing/character issues.
Really, I think the Star Wars films are in the order in which they debuted in terms of quality. Maybe have Star Wars and The Empire Strikes Back be interchangeable with #1 and #2 and Attack of the Clones and Revenge of The Sith with #5 and #6.