Looking back at it, the story is flimsy and then I'm being very mild, and unlikely doesn't even begin to describe the events in the movie. But do note that I say "looking back at it", because during the movie I was far too spellbound to be noticing such things. Definitely a thrilling experience, the plot is really just secondary.

As far as the acting goes, is it just me or are both Bullock's and Clooney's characters always more or less the same? I have the feeling I don't even know how good an actor either of them is as there seems to be so little variety in the characters they play...

Anyhow, variety or not, Bullock's usual persona works well enough in the role, and it's the big dark emptiness that has the real starring role, anyway.