I've been to several gangbangs, 5-8 years ago. Its good fun with the right girl.
The problem these days is that escorts at gangbangs makes you feel like your on a pay-meter, hurry up fuck her let the next guy have a go, and its when there are men there who take FOREVER fucking the girl and some of them then STILL don't even cum until later. Its all a bit rushed these days, they are all advertised as something like £100 for 2 hours 6 guys max.
Bring back the days when there was some girls doing it all evening until she was too tired to carry on, for easily less than £100 with no limit on the amount of men who attended - typically up to 25 men on 1 woman from my experience. The best one I attended was with a mid 20's Czech swinger woman while her boyfriend watched and later participated, she was a right laugh she genuinely loved everything about the experience, fucked 25 men repeatedly over 6 hours she literally loved every moment and swallowed over 40 loads of cum - and she licked up every drop. I shit you not even in the slightest.
I've not been to any other gangbang since that one as she was just out of this world amazing, no escort was ever into a gangbang that much. Now I see escorts profiles advertising these gangbangs stating so many limitations on everything. Screw that.