As a dude, I'm quite impartial to regular, doctor, or boss' chair.

I've been the recipient of the kneeling one, and I found it quite awkward, like "well, what do I do know. I don't really know what to do with my hands, and I don't want to put it on the back of her head to imply she needs to suck me off better or anything".

If I felt goofy, then I'd probably twiddle my thumbs in a very silly way to try and illicit a giggle from the kneeling position.