Ahh, nostalgia. Not for the movie: I'd never actually watched it before. (The teacher did put it on at the end of the last day before winter break or some such in fifth or sixth grade, but I was too young at that point to sit through a whole movie and did other stuff.) But I had an Intellivision. So I spent hundreds of hours of my childhood playing Tron Deadly Discs, and dozens on Tron Maze-A-Tron, and, uh, a few on Tron Solar Sailer. So, oddly, watching Tron at long last was like seeing a movie based on some rather obscure (but dearly beloved) Mattel cartridges rather than the other way around.
And it wasn't what I was expecting. I thought it'd just be guys running around some cheap-looking sets in blinking suits. It's actually a feature-length CGI cartoon (from 1982!) that happens to have some live-action spliced in. And the live-action is also surprisingly stylish: the high-contrast black and white with colorful glowy bits recalls the silent era, complete with tinting, and works far better than regular color would have. On the CGI front, I certainly prefer Tron's artificiality, its simple and thematically appropriate polygon rubble and landscapes, to modern CGI that tries to pass itself off as actually real and fails.
It's also a nifty little world the filmmakers have cooked up, basically the product of grabbing a vocab list of early-80s computer terminology and free-associating. The "video games" are neat (even the ones that didn't make it to the Intellivision). The girl is awfully nice to look at. Plot-wise there's not much to speak of, and thematically... well, it was the Reagan Administration... so, yeah, this is more spectacle than narrative. Which means that as a movie, it kind of sucks. But as a piece of pop art, it's very cool.