I did notice the lack of muscle definition, and the pain tolerance (this girl in tri training...tried to do our ride on a mountain bike...man was she a trooper)....but I have never noticed them being bad climbers...but there's not any real hills here, but even on the "bumps" they do very well.
I noticed I have to rip on the cranks to go up those bumps as easily as they do....but I'm 220lbs, and they are about half my weight.
The other thing I noticed is they are great sprinters, but I have never seen any females accelrate as violently as the male riders during these sprints, who tend to accelerate like bats out of hell (myself included)....just an observation.