I'm a lean-ish 6 foot, 215lb at the moment, I don't buy into the belief that climbers have to be ultralights. I've worked hard on my climbing while coming down from 260lb over the last 2 years and I can climb with at least 80% of the ultralights I come across. On short steep climbs that take no more than 60 - 90 second I get out of the saddle, shift up 2 or 3 gears and generate enough torque to visibly flex the frame and bars, and if I get the jump on the little guys I sometimes even manage to drop a few.
What I'm saying is that we clydes can hammer hard uphill if that's how we train, ofcourse training to do that is really hard, you have to hurt a lot.