Oh my, I haven't answered this yet...
Personally, I think if you've never taken a girl private before, you should pick your favorite model and do so at some point. Just once. See how you feel about it before you make a decision.
If you find you like every situation, why does it have to be one or the other? Why not, one month, spend slowly, and the next, blow it all on a pvt?
When all is said and done, you've spent the money on the tokens already, so use them in a way that gives you the greatest happiness. In Personal Econ 101, we were taught "If the money is gone, do whichever makes you happiest". We were given the example of playing tennis indoors vs outdoors. We were told the following things:
-Playing indoors requires a reservation with a non-refundable fee at the time the reservation is made.
-Playing outdoors is more flexible, no reservation needed, and the fee is included in your club membership.
The hypothetical tennis partners prefer to play outdoors, not because of the fee, but because they like to get the sun and fresh air. They always play on Wednesdays. The weather forecaster says it might rain that week on Wednesday, so on Monday they reserve the indoor court. Wednesday dawns sunny and clear.
Since the money is already paid, already spent, the fact that it costs money shouldn't be factored in. Instead, they should play outside because it is what will make them happier.
It's the same with your tokens. You've already spent the money. You're left with tokens. Do what makes you happiest with them. Whichever model you give them to should appreciate them no matter which way they come.