In short: to each his own, and I respect everyone's right to monger as they see fit. We're all different, with our own preferences and budgets. It wasn't always this way for me, but nowadays I happen to not be constrained by money.
I've tried AMPs, and they really aren't my thing. I can see how people may prefer AMPs for various reasons: not knowing who you're getting is exciting and the excitement makes your dick hard, you don't know when you want to fuck and enjoy being able to pop in whenever, etc. I happen to prefer white chicks with whom I can communicate, and I'm a busy professional and prefer scheduling my time with women. Scheduling a rendezvous with a girl you've previously met is very easy, and you know roughly what you're getting every time you visit.
I was lucky when I first began using switter: I got a noob who didn't require verification for an in-call visit, and I used her as a reference to see other girls, and now I have a stable of hot white chicks at my disposal. Sometimes I see new chicks, and if I don't like them, I don't visit them again.
Indeed, there are a ton of overpriced, ugly whores on switter, so you have to do your homework.