Wouldn't know about being "high" because I don't do drugs. I know when you have a buzz off alcohol it's slightly better, but when you're trashed it's more likely you'll have an erectile dysfunction.
I don't think it makes it feel better. Although I suppose drugs/alcohol does naturally make you feel good. It definitely makes me last longer though...
I am under the influence or high near every time I have had a sexual encounter tbh. The last time I was fully sober while doing so was my last girlfriend I had years back. I honestly like it better while intoxicated it's just much better and does feel better imho. However I don't mind either way.