Glad to hear you liked both the movie and your first TRUE IMAX experience!
And yeah, I really don't know what people were expecting from a Tron sequel? I mean, it's TRON. It's a cult classic & visually stunning for its time, but the movie is fun even with it's flaws. I thought Legacy was a fantastic sequel, and the soundtrack is easily one of the best soundtracks in a long long time. Also, snow is fun!
So is the 3DS!
Oscar fucks should have nominated it. Honestly, I hated The Social Network's soundtrack... But I hate the oscars anyway, so meh.
I really don't know what was wrong with the movie. Aside from being a sequel that people who haven't watched the original would be a bit confused watching, but still... it had everything I wanted, really. Amazing visuals, lots of callbacks, pretty much everything made sense (yes, even the food and the city. It's pretty much explained Flynn redesigned the grid so programs would be a civilization instead of worker bees) so what was the problem?