It took me a couple viewings of the PT to figure it out but here it is. Don't get me wrong I like the PT but the OT is still better and more enjoyable to watch over and over again. At first I thought it had to do with the nostaglia of the OT that made it the favorite series but I don't think that's it any more.
The PT is just too freakin difficult to follow. The plot is WAAAAAYYY too complex. I remember leaving the TPM theater scratching my head trying to remember why there was a trade blockade, what happened in the Senate or how the Sith fit into all of that? That doesn't make for a good movie.
It's seems that GL knows that Episode 3 is the big pay off that will set up for the OT. The PT, in his vision, needs to be planned as a whole with each part building on the last. The OT wasn't like that. Each movie had a beginning, middle and end. Sure there were a couple unanswered questions after ESB but we knew who the bad guys were and the background explanations were short and sweet. Now were building to a 3 movie explaination of why/how Palpatine became the Emperor. 8 hours of background information for a character that makes an appearance requiring no background information in RotJ?
In the OT the bad guys were just bad, no questions asked. Well we're now spending 3 movies getting answers to those questions that no one was asking. Sure we were all a bit curious how Vader became so evil and how Luke and Leia were associated with that but just have Obi Wan say to Luke "your father couldn't control his anger after his mother was killed." Bam! We saved 8 hours right there. More time for space adventures and less time needed watching Space Senate Hearings. Star Wars CSPAN? No thanks.