There were some great ideas in there, but i don't believe the final product was as good as it could have been, Lucas should have made a better structure for the Prequel Trilogy than he did and hired better people to rewrite his treatments. If he wanted to Direct, he should have tried Directing other passion projects in order to prepare himself.
While Episodes II and III are the ones with the more important information, i would say that Episode I's the least problematic. Lucas should have had the clone wars start in Episode I or even start before that, that film would be Obi wan meeting Anakin for the first time and the development of their friendship, II would be the middle of the Clone Wars, and III would be the rise of the Emperor and Anakin's fall. As it is, it seems like there are large chunks of plot left between I, II and III, while the original trilogy flows more naturaly, even though it also has years of events that happened in between.
That said, i think Episode III had the right structure:
Starting with Obi and Anakin's final adventure before the Jedi fall, then going with every main character having to deal with some problem (Anakin is being seduced and trying to help his wife, Obi-Wan is having stuff from the clone wars to deal with, while Palpatine is slowly taking over), finaly culminating with the betrayal of the Jedi and Anakin vs Obi-Wan. The film does do a decent job at letting people know what's happening, you could put this film without having watched Episode II and you don't miss much.