I think a lot depends on the guy's personal life as well. Married men, i think, are more into playing the field rather than sticking to one or 2 regulars. Getting away from "routine" is why we are seeing escorts to begin with. I do have a couple ladies I gravitate back to, because they treat me well, we click and whatnot. But I also enjoy seeking out new experiences as well. I'm not very active this year hobby wise, I think I have seen 10 different ladies. 2 are the regulars I mentioned, 3 have been repeats with other ladies I have seen and the others have been new to me.
From what I see in the single guys I know personally in the hobby, and the ones identified as such on these boards, many seem to be looking for that "replacement" for a wife/gf in their life, in the bedroom at least. They might go through the exploration phase of seeing a bunch of escorts but they seem to settle down to a couple ladies at most that they are most comfortable and compatible with.