I'd say comparable to Return of the Jedi
Not as good as The Empire Strikes Back. Much better than the two pieces of crap masquerading as Star Wars movies before it.
My short summary is that George Lucas' abilities remain what they were (great at action, dialog sucks, cute characters suck) but he was able to make this movie play to his strengths rather than his weaknesses.
In the movie it is obvious that Anakin's fall is massively compressed. Some of that is the format, there simply isn't the space in a movie to show major emotional progressions like that (particularly not when you're trying to keep the pace up). There are hints about how much time is involved - for instance Padme's growing belly is an indicator of how many months passed between glimpses - but that observation strikes you on an intellectual, not emotional, level. It feels like, "OMG, that pregnancy went fast!" rather than "Gee, lots of time just passed". I'd have added more such cues, for instance references to how many months Anakin has been on the Jedi Council.
Oh, one other note. Someone should have made Natalie Portman spend some time in a maternity ward. She's supposed to be dying in childbirth, not relaxing after the easiest childbirth on record!
Cheers,
Ben
I have come to believe that idealism without discipline is a quick road to disaster, while discipline without idealism is pointless. -- Aaron Ward (my brother)