I have a pair of Irideon "WindPro" breeches, got 'em in ladies large as the mens version wasn't available with a full seat. Waist and length are just fine, but there is significantly more room in the hip/thigh than the mens breech. Not enough to be a deterrent for me, 'cause I'm not out to make a fashion statement, but the difference might be more of a problem going the other way.
I guess I'd say that if you have much of a bootie, you will want womans breeches.
FWIW, WindPro = nice :-)
Steve Jernigan KG0MB
University of Colorado