I'm not sure those two sets of things go together very often though, at least early on. Now if I'm in an LTR and within it, the woman makes getting sex fast and easy, that is optimal. But if it's fast and easy on the front end for you, it likely will be the same for others.
personally, i always just thought it was a sign of how much the girl likes sex, if she has sex with you fast and early then she must clearly like it a whole lot. but if she wants to wait a while, she probably doesn't like it too much. (obviously it's all relative, but if a girl doesn't have sex til date 4 i'd bet money that she has much less of a sex drive than the girl who gives in up on date 2, but as long as she doesn't make you wait til date 10 then her sex drive is probably within normal deviations)
ideally you want a girl who likes sex as much as possible for a relationship so that you can get laid all the time(the last thing you want is a girl doing it for you, if she was only having lots of sex because it was the "honeymoon phase" of the relationship then you'll have a problem)