not a provider, but I'll share my experience
I trim, right down to the skin with an electric shaver and ALL the women I have seen (both civi and providers absolutely love it). I would have about 1/16-1/4" at most. some loved it so much it got me some extra mileage.
I am not saying that a hairy crotch and ass means you don't take care of yourself, its just a different level or preference in personal care.
BUT as Zoey said, its a matter of preference. I just have not come across a woman that has a preference for hair . . . yet. when i do she will be disappointed. I personally dislike body hair on myself and my women.
I do not shave with a razor blade, the thought of that super sharp instrument on such a critical body part makes me shudder
face shavers were designed to work with the contours of your face, not balls. the skin on your balls is much softer and more delicate than your face, and would experience terrible razor burn as well as cut easier, since the skin folds very differently to face skin.
I have found that the best electric shaver for getting the job done on myself are the women's bikini shavers, primarily because they have the comb teeth on the lowest level very closely spaced. Most men's trimmers are usually for head, chest and back hair. The comb teeth on the lowest level are spaced a bit further apart and are also bigger. this causes them to dig into your skin as well as cut skin AND not cut the hair as low as the women's
skin cuts are a big safety concern when seeing a lady as you do not want open cuts in those areas, esp when body fluids may come into contact with it, so shaving before an appointment is not advised. prob a day or 2 before to allow some healing time.
as for getting to your ass crack, the women's trimmer is the perfect tool, since the head is smaller. It would involve some twisting and contorting in the bathroom to get it all, since you are kinda flying blind when shaving back there, but with a bit of time and patience you can get it as smooth as the front. the womens shavers are easier to work with and can get ALL the hair off your balls.
also teh electrics do not require shaving cream or for your skin to be wet. just moisturize after you are done.
hope this was of value