DRrh, I have been getting erections with female providers much if not most of the time for many years now. Sometimes it is partial, sometimes complete. (I am pretty sure it stems from three specific, and long, experiences I had in hospitals at ages 10, 14 and 17, many years ago.) What I find surprising about this and similar discussions is that I have not gotten any -- and I mean not a shred -- of negative reaction from any of these women in all that time. The most typical reaction that happens is a type of professional distance or detachment from it - not mentioning it or referring to it in any way. But also typical is a sort of amused or friendly (not sexual) acknowledgment of the situation that I find hard to pin down. That was my purpose in asking Susie about it.
One experience I had that was surprising to me, yet possibly suggestive of the cause, was during a testicle ultrasound done by an enormously fat and unattractive female technician who used a female chaperone, telling me it was for my own good as well as hers. During it, I did not get an erection. I was repulsed by her looks, attitude, lack of good grooming (for wont of a better term), etc., and that might well be the reason I did not get an erection that time. Overall, that incident had a element of the surreal about it that in retrospect I find humorous to this day. Yet it is worth noting that she almost alone among my various female providers was totally unattractive to me. So my getting an erection may require some degree of attractiveness by the women.
What I have made from all of these experiences (several dozens now over three decades), given that I read accounts of various negative reactions on boards like this or of studies such as the one you cited, is that either a lot of people make a mountain out of a molehill about the matter, or I am damned lucky, or my various female providers are an unusual or unusually sophisticated lot. But I am comfortable with them and they seem to be with me and I pretty much plan to continue with them as is. I see no advantage or need to change them. My PCP in particular and I have a great relationship and I have been going to her for about 15 years now. I trust her completely and she has done some important work for me. My urologist is a woman, and though I have only seen her four or five times (most recently for a cystoscopy), she seems the most blase of all of them about it. I have nothing against male doctors but I do think I have had better communications with and especially from the specific set of female doctors I have encountered compared to male doctors, so I'll stick with them. At my age, I am not easily embarrassed, anyway.
I was a little surprised about Susie's reactions. But the whole matter may just be one those situations where you have to be there, to actually experience it, to judge it properly.