Surprisingly the adverts & trailers weren't all that dreadful. I don't think I'd like either the new Pirates of the Caribbean film, nor Gnomeio and Juliet, but the trailers were pretty funny (and I liked the central conceit of Gnomeio & Juliet where the garden gnomes come to life when the humans aren't looking).
Onto the film itself - I've never seen the original Tron nor had I bothered to read anything about the film in advance, so I was coming at it fairly fresh. All I knew was it had something to do with getting into the insides of a computer programme. So I was pleased that the start of it got us up to speed on the previous plot-line.
Here follow some rambling thoughts about the film. First off I should probably note that my taste in films runs to things that are mostly loosely hooked together action scenes - plot heavy stuff means I'd almost always rather read the book, it's gotta be car chases, fights etc, visual spectacle. And Tron: Legacy definitely delivers on that front, so I thoroughly enjoyed it. SOME SPOILERS: I suspect you can pick nits with the plot ad infinitum but I don't intend to, other than mentioning that I thought the rationale for how special the ISOs were was a little confused at times. I understood why they were special in the Grid (spontaneously formed life, how cool), but then there was something about how important they were for the real world that I never got a handle on.
I thought the 3D was well done, although fairly subtle - so subtle that in some ways it might as well not've been done except to sell more expensive tickets. Tho having said that, I liked the way it was 2D for the real world and 3D for the Grid, it was a nice touch. I also liked that we see Sam Flynn being badass outside the Grid first, so when he does stuff inside the Grid it's more believable. And I liked the other inside/outside echos - for instance I'm pretty sure in the TV footage for the immediate aftermath of Kevin Flynn's disappearance it included a speech Flynn gave, that was echoed by Clu's later speech to his army. I thought the actress who played Quorra was really good - she managed to be convincingly naive yet extremely competant in some things, and to convey how she'd been living with god for the last however long (and the echo there with Sam & his dog was a neat touch). Castor/Zeus was also neat - reminded me a lot of the Merovingian in the Matrix films, as well as being very Bowie-esque. Lots of other film references through the whole thing too - I spotted a lot of Star Wars ones ("I'm not your father" being my favourite, I think), as well as various Matrix ones.END SPOILERS
But mostly I just grinned at the over-the-top actions scenes and giggled at the humour :)