Do they actually 'do it' (the mechanical aspect) better? No.
But there is so much more than the mechanics. There is the woman's expectation that is a huge part. What is she looking for; the forbidden, the taboo, the myth, the excitement? All these contribute to the arousal aspect which, in her mind, leads to great sex.
If a woman was turned on by X, Y, and Z traits (guy is tall, well built and has a beard) and that guy falls into her life, then she'll probably more sexually satisfied than an equally skilled (mechanically) guy that didn't fit her profile.
Conversely, she could meet a guy who is socially inept, balding, and overweight yet very well equipped and a demon in the bedroom, but he won't stimulate her as much as her ideal guy would.
So, in short, I'm of the opinion that it's at least 75 percent mental - what the woman wants - that gets her off.
Finally, keep in mind one thing. We're in an artificial environment here. Everyone likes variations of the same thing, or else they wouldn't be here. You could go to other sites, catering to other interests, and find just as much passion for that as the folks in here feel about their interest. So don't get wrapped around the axle thinking that ALL women LOVE Black Men more than anything else. Sure, there is strong interest out there, and it is popular and gaining social acceptance, but don't think it's the only thing turning women's heads!