Somewhere in the multiverse, there is a good TRON sequel movie, perhaps even several different good versions out there, but this isn't one of them. We saw it in 3D in the theater, which neither helped nor particularly hurt the experience, but did induce a little eyestrain and made an already dark movie even darker. I will probably not be going to another 3D movie anytime soon.
Like Tycho, I have a lot of questions and concerns, from the worthiness of the bad guys compared to Dillenger/Sark and the MCP from the first film, to the number of scenes that have no energy/don't add anything in terms of character development or plot (I'm looking at you, dinner party and bad guys searching Flynn's place, to name two), to the fact that Zuse's nightclub brought on painful flashbacks to the Merovingian. It's a shame, really, because while I liked the actor who plays Zuse in Frost/Nixon, he's wasted here. Likewise with Jeff Bridges. I can't tell whether he's disinterested or has lost a step, but the great spirit that helped carry the first film out of mediocrity is gone, and he appears caught between playing his original character (with a dash of the Dude) and Obadiah Stane. Garrett Hedlund is all right, I guess, but his character is a poor mix of Bruce Wayne and the Chris Pine Kirk. It's Olivia Wilde who comes off best in their scenes together, and I'll actually be looking to netflix something else with her in it.
Off the grid, it's a crime that Cillian Murphy doesn't have more to do. I really liked his cameo and think that his role is expanded in one of the good versions out in the multiverse.