We just got back from seeing it, and while not a masterpiece by any stretch, I found it to be pretty enjoyable and thought provoking. I thought the acting was fine, and this was not a film where character development took any kind of priority, although I thought the last scene and its ambiguity showed a change in Cobb's outlook.

As far as a CGI film, I thought it was one of the best I've ever seen. The CGI was very well integrated into the rest of the film. It is difficult to try to present a dream world well on screen and a lot films have failed miserably at it. A lot of what they were doing contradicts most of what I remember from the Dream Theory classes I took back in college, but its a movie, after all.