I have to say I have had the exact same experience as you Writrboi! I have always been mostly bottom but that was because my experiences as a top have been a lot less fulfilling, about 4 or 5 times. This past Friday I tried fucking a guy for the first time, which i hadn't done for months!!
haha, and i have to say it felt like I was fucking nothing. I was wearing a condom, so maybe that will lack a little sensation but yet it was almost to me like there was nothing there. I have been with women before and it was not the same.
Yes I am mainly a bottom and trying to become more like a vers guy to pleasure my man, but if it's such a hole where I don't feel anything, no wonder I prefer the position of bottom I am in!