In my opinion, it started very slowly and that first chase is crap. The way it handles/perceives technology is also crap, it's like they decided that technology would be key, but then just made up everything about it without any reality thrown in.
That said I certainly enjoyed the movie overall and the baddie is probably my favourite bond villain ever. Most decent villain was the combo of Jansen, Bean and the other bloke in Goldeneye.
QOS is an awful film. Casino Royale is by far Craig's best. Sky fall is in between, beating all Brosnan efforts except possibly Goldeneye and beating many other bond movies too. Still doesn't quite reach Goldfinger or one or two others if you take into consideration the time they were filmed.