I saw this last night at a screening in St. Louis. Overall I really liked the film. It is certainly ambitious, actually has something to say rather than vaugely hinting at ideas, and I think for the most part acheives what it sets out to do. The film certainly has its problems though, largly having to do with how and when the film decides two switch between its several stories. While overall I think each story recieved enough screen time, the way it is broken up can make things seem too short. Rather than following the format I've heard the book takes, telling half of each story and then following up with the second of each story later, the film cuts between things based on certain story beats, or events or even just similar shot framing. To a certain point I can see why they did this but in others it felt like they didn't trust the audience to see the parallels and felt necessary to show them, even if that meant cutting to another story after only a minute and then back to the story they were telling. Most of the individual stories told in the film are compelling. In someways this is actually problematic because even with some of the smaller stories, like an escape from a nursing home, I felt I'd rather just watch them as their own films. There was only one story that I felt was unengaging.
The experiment with the casting was certainly interesting and often entertaining in its own right and never all that distracting or disruptive. I could certainly see their aim in some respects, especially with Hugo Weaving consistently representing a force of Evil. With some of the casting their was no real logic though. Some of Tom Hanks casting is particularly problematic.
Some I spoke to, including my girlfriend, found the film a bit of a slog to get through. It is certainly long, just short of 3 hours, but I had never felt it was tiresome. Some were disappointed that the connections between stories were more thematic rather than explicitly through the consequences of actions. I can understand this complaint, since one of the major stated themes of the film is how your actions echo throughout time and seal your future but the ways we affect one another is certainly represented in the film.
Personally one of my only major complaints with the film is that for the majority of the stories, the climax take place offscreen. It can be a bit frustrating or at least underwhelming after almost 3 hours.
All of the acting is top notch, as can be expected.
Its certainly a film I want to see again though I plan to read the book before I do. There's a lot to chew on.