For most UK climbs I'd say it's usually all about power because they're usually quite short. Can't think of many climbs in Britain that you'll be spending more than 20 minutes on. Not to say there aren't any of course, but not many.
If you think of something like the Tour of Flanders, the successful riders in that are not your typical weight weenie climbers, but Boonen/Cancellara/Sagan all have a whole lot of power in their legs. I'd guess that Flandrian style climbs are more common here than Alpine style ones.
Obviously down here in London we sure don't have any long climbs really. The longest I regularly do is around 3km and takes around 8-9 minutes to climb. A world away from the 1h50m it took to get up the Stelvio.