I have been a devoted TRON fan for most of my life. I finally caught the sequel in a second run theater in 3D even and, well, man, I didn't hate it, but it really felt like it was missing everything they put into The Next Day. The corporate espionage angle, the idea of a giant looming oppressive corporation was entirely gone.
The Next Day should have been the end of the feature film. I would have walked out of the movie grinning ear to ear.
I enjoyed Legacy, thought the 3D was used well and it felt right for the world of TRON. I also would have enjoyed seeing more of the grid, more games, some more of the next gen recognizers, and I was hoping for a tank battle!
I thought the character of Flynn was pretty much wasted and just downplayed in the writing too much. Tron was totally wasted.
I love the idea in The Next Day that Flynn was calling Alan Tron after the first film. That's just flat out cool.