It was okay. I just saw the 3D version earlier today at Cineworld in Sheffield. I thought the 3D was impressive, it's come a long way since the crappy red/green glasses of the 80's, but it's still far from perfect 3D, i noticed quite a few "shadows" around the characters, particularly during the dialogue heavy moments.
On to the film itself though, i'd give it about a 7/10, imo there wasn't enough action until the last 20 minutes or so, and by then it was a case of too little too late, but that final 20 minutes was definitely very good. I really didn't like this motion capture style though, i kept thinking throughout the film that it would have been better if they'd done it in the style of '300' and actually had real actors against CGI backgrounRAB (although i suppose that would have meant no Ray Winstone, and it would have probably presented problems with Angelina's nudity). And what was up with John Malkovich? He sounded like he was reading his lines in over the phone!
I'm glad i saw it though, if only for the experience of the 3D. That said though, did anyone else's showing have the trailer for the 3D version of 'Journey to the Centre of the Earth' starring Brendan Fraser? The 3D on that didn't look good at all, i felt like i was going cross eyed, and it made me feel quite sick. Maybe 3D should stick to cartoons, because it definitely doesn't suit "real" films if that was anything to go by.