Generally I don't repeat too much in the hobby, because if I want a deep level of intimacy and companionship I'll have a regular girlfriend. I hobby because I want the sexual fireworks that comes from meeting someone hot that knows what she's doing. There's something intensely erotic about going to a woman's in-call or having a woman knock on my hotel room door, having never met her and knowing we'll be playing together shortly. It takes a really attractive women with a lot of skill and personality to overcome that for me.
I do repeat occasionally with gems that I've met because not knowing the girl that I'm meeting also sometimes means she might not be that attractive to me or she might not have good technique, etc, so seeing a 'known quantity' is sometimes a better choice. The problem that I find is (especially in the SF area Korean escort market), their availability is somewhat inconsistent, so a girl might be here for a month, might be here for 3 months, might do that and then come back 6 months later, etc. For example, there was a girl I've described as the "Korean Jennifer Connelly" (think
this scene, but with a naked Korean girl doing P2P) that's one of my all time favorites but didn't get to see her much. She had the looks, the illusion of passion, and she had a great personality so she was fun to talk to between pops.
It's probably better this way, since I'm almost positive I'd fall for the wrong girl and she'd spurn me or even worse, use me for money and then spurn me. I'll just continue seeing various attractive girls and occasionally having a truly mind-blowing experience in bed that I can repeat a few times while she's around.