I've been a few times. It's pretty seedy. A Chinese guy will open the door and lead you in to a flat to meet the girl and stay in the flat with you in another room. The rooms are normally set up with music and fairy lights to distract from how grim they actually are. If anyone is familiar with old Soho walk ups, it's a similar vibe.
The reason I've been back repeatedly is that I met a decent looking 20 something girl first time, bit of a plumper the next, followed by an enthusiastic stunner, and then two that I should have spun around and bailed on - t's pot luck and sometimes you win. Although the physical appearance of the girls is mixed, service has always been pretty ok.
Even though the girls never seem unwilling or unhappy, if I'm honest, the set up has a bit of a 'trafficked' feel I'm not comfortable with. But at that price and because of past wins, I'll probably keep going back.
