In reply to TobyA:
I use the 2012 & I've looked at the 2006. According to Steve Scott's editorial note there are over 200 new routes for 2012 (rough estimate getting on for 800 entries in the index). Even so I'm not sure it's worth updating unless you get particularly active in the area. I have a few gripes with the 2012 guide:
It now weighs as much as an ice tool. Not sure how you'd solve that without splitting the guide or leaving routes out, neither of which would be ideal, but it feels like lugging Cold Climbs up the crag with you. Sadly it doesn't seem to make finding the right conditions any easier.
The topos themselves are small and crammed with gratuitous borders abounding, leaving you squinting to see crag details, which are further obliterated by heavy coloured lines and numbered boxes. Specs essential, preferably x-ray.