... is that I pretty much know after the second date if there will be a third, a fourth etc dates. Sometimes the first date can be a little awkward, but if I have a good time I'll usually do a second date. But if after the second date we haven't "clicked", I'll likely not do a third date.
I find that my second visit with a lady has been invariably better than the first. I don't know if that's because I'm more comfortable, or perhaps because the ladies try harder knowing they have a potential regular on the line. Or they could be better at it because they're better informed about my likes and dislikes.
YMMV, goes without saying. But is the better second date (BSD) a thing in the hobby? If so, what is the standard explanation?
I've had several that the second was better too. I think it's everything you said plus that she is more comfortable with you, just like you are with her. She's not spending the beginning of the visit wondering if you're uncle LEO, or if you're going to knock her around, or ask for something freaky involving a weed eater and a live chicken.
Sometimes, I'll have a second that's really a let down from the first, the sophomore slump. A lot of hobbyists talk about the thrill of meeting someone new, and that the passion of that first time will never be equaled so they almost never repeat. I don't really see it that way, but I wonder if some providers do. Sometimes, after a slightly slumped second visit, I'll try one more time and the third visit beats out the first by a mile. Maybe she was just having a bad day.
Knowing that the first session was very good, there is an anticipation of having another very good session, and this becomes somewhat self fulfilling.
It's after the fifth or sixth session, when often the quality begins to suffer, that I decide it's over.
Reality takes time to sink in
2nd dates are the best! I'm excited that he enjoyed me enough to book again and I'm thrilled at the idea of a potential regular.
also, like you, more comfortable, you know what you're getting and what to expect. Not worried if its LE or that they're gonna be stalkers. 
xoxo,
Lexi
... is that I pretty much know after the second date if there will be a third, a fourth etc dates. Sometimes the first date can be a little awkward, but if I have a good time I'll usually do a second date. But if after the second date we haven't "clicked", I'll likely not do a third date.
third, fourth, etc.
Once two people get comfortable with each other, they become more relaxed in each others' company and more willing to please.
It's impossible to discuss likes, dislikes, fantasies, etc for a 1st date due to legal issues. But a 2nd date is much easier, much more open, and a decent provider will be there for *your* pleasure. Occasionally the 2nd date ends up worse for w/e reason (my assumption is the provider didn't much enjoy the first date, and thus wasn't all that happy hearing from me again). But generally, 2nd dates should be and are better.
Still waiting on that provider I could envision seeing for months on end though.