...if you want to experience as many different sexual stimuli as you can while you can either physically or financially,then go for the notches on your pistols, you if want to enjoy the facsimile of a relationship without the hassle of seduction and dealing with pms moods like in a real life relation, then go for the repeat, ...
I couldn't have said this better.
There's also the issue or "reliability" and making sure you get the most out of your escort dollar.
If you're into different experiences, then go for a new girl each time.
But if you want "reliable" experiences where you feel comfortable from the get-go, go for repeats.
When you repeat with an SP, if you have a positive relationship, then there's a trust/comfort level you have that you just don't have with one-timers. With one-timers, she has to figure out what works for you, you have to figure out what works for her. With repeats, you get to know one another's likes/dislikes and it can make a session go a lot smoother. Plus, you never know if your personality is going to "click" with a new girl. If you choose your repeat wisely, you'll choose someone you'll actually enjoy talking to between SOGs.
So, in other words, I don't have a lot of cash to throw into this hobby so I like to make sure that when I'm paying for a lady's companionship, that I can be assured that I'm going to enjoy that time as much as possible; as opposed to the crap-shoot you get every time you call a new escort.
That's not to say you can't have the best of both worlds. Go for your repeat(s) when you want to be assured of having a good time and go for a new one-timer once in a while just to spice things up with something new and exciting. It's your money, you can do whatever you want with it.
And that's not so say that you have to stick with ONE repeat SP. If you're got the time and money, you may want to cultivate a few of these escort "relationships". The problem with putting all of your eggs in one basket with only one go-to escort is two-fold: 1) If she's booked, you can be left feeling horny and frustrated; and 2) Eventually she might take you for granted and stop making an effort (which is kind of what happened to me a long time ago).