While I have never trained under an actual woman sensei, I have trained with women sempais, which is very close to your post point and echoed by others.
The 2 women sempais I remember most were a brown belt with extensive martial experience and a relatively less seasoned green belt. The brown belt was of small stature, 5-3 or so and light in weight, while the green belt was nearly 6 feet and of solid weight.
The brown belt was very fluid, crisp and fast. Her moves and kumite reeked of skill and the martiality that David spoke of that transcends gender and commands respect. She kiced butt with exquisite control!
What the green belt lacked in skill, she made up in strength and she just plain kicked butt! I remember when we did some pure physical strength and balance/tug-of-war rope work and she would not be moved!
Now, I am but a small fry in martial rank and no power lifter, but still, I found nothing wanting in the exchanges with these ladies from any perspective you could think of - skill, ferocity, strength, teaching ability, etc.
Now, our dojo is particularly unique in that we draw mostly women in the military and/or law enforcement, so that they are probably in far better condition and much more acclimated to the martial environment than the general population of women. But, probably most women of rank are, like their male counterparts, a rare breed anyway.
Unfortunately, the green belt was transferred out, and the brown belt semiretired from training after childbirth.
Osu to them both wherever they may be!