In reply to ivebittenoffmorethanicanstu:
It sounds like we're climbing at a reasonably similar level. I've got the Rockfax Western Grit book and have been more than happy with it and it works for me. It's dead easy to spot the lower grade routes as the routes are colour coded with colours that actually look different (not a feature of every guide book I've looked at so far!).
Best advice though is pop into your local shop and see skim through both books. See which offers the most suitable coverage for the areas you're interested in and see which format/style works best for you.
Mike.