In reply to Euan McKendrick:
It's not just climbing shoes, but mountain boots too. I've had this conversation a number of times with UKC ed Dan when we have been working on reviews. I'm under 5'10, Dan is well over 6' but more importantly I'm 41.5/42 in boots, he's about 45 or 46 I think.
I'm not light by any means but have found B2 boots perfectly good to frontpoint and kick steps in, whilst Dan has found similar boots really flexi for their supposed B2 rating. Give me a place to stand I will move the world, and all that. Or give me a big enough foot, I will bend the B3 'rigid' climbing boot!