It all depends on how one determines a 5. If this were school and a 10 is an A+ and 5 is an F, I would go with the one 10. If on the other hand, a ten is a Victoria's Secret Model and a 5 is an attractive but average type girl, then it is more difficult to answer. It would depend on my mood. If I just want to indulge in the hottest looking girl around, I'd go with the 10. If I were looking to get my rocks off a couple of times, I'd go with the two 5s. To be honest, I really haven't seen too many 10s worth answering the question. I had a SB who was super model hot, but our arrangement was very budget friendly, so I was used to having my cake and eating it too.
As for someone new vs a regular-- both
Again, I find myself battling this question. With the SB, I could get my fix from a reliable girl but still have the option to taste new honey every now and then. It all depend on the flavor of the moment. If I want something exciting, I'll seek out the unknown.