I saw it on Friday evening. I thought the first hour was a bit clunky, there were changes from the book but over all once it picked up, it worked very nicely. I enjoyed it and i agree, Aidan didn't have nearly enough air time. Robert Sheehan is very charming as Simon but I found Jonathan Rhys Meyers to be very pantomimish.
The sequel is in production so fingers crossed there is more screen time for Aidan, it was lovely seeing him on screen and he makes for a gorgeous, sexy werewolf. Will be getting this on DVD methinks (And i've read the first three books)