I had a similar reaction to Scalzi's Old Man's War. Fascinating idea, competent execution; meh. I never followed up on the rest of the series. May try the movie when it comes out -- maybe the change in medium, as well as the added perspective a director will bring to it, will make the story click for me.

Interestingly, I enjoy reading Scalzi's blog very much. I particularly like his essay on the ethics of downloading unauthorized electronic copies of stuff you've already paid for in print.