I won't bother with what it's about, since (a) you've probably already seen it, and (b) I have no idea what it is about.
Okay, I kind of do, but I'm too lazy to type it out.
First of all, good casting. My favorite out of everyone is Joseph Gordon-Levitt, and I hope I can see him in the upcoming "50/50". So no complaints about any of the actors.
I did get annoyed with Leo's character at times. I know he went through a traumatic experience and all, but I wanted him to just push his issues aside for five minutes and get the job done without making his problem everyone else's problem. And, as expected, the story could at times be confusing, as intended by the filmmakers, but I managed to understand what was happening most of the time.
Overall, I enjoyed "Inception", but I wasn't overly impressed or blown away. I think it was overhyped, which is nothing new when it comes to popular movies.
My grade: B+