I've had 3.
The first was unexpected, the girls mate came in and was joking that her mate must give shit blow jobs because I hadn't come yet; next minute I know they're competing with one another!! I fucked both of them and paid no extra! It was good, but not as amazing as I thought.
The next one I had was unbelievable. Two stunning blondes. One was a little compact thing who used to let me come fuck her off duty and the other was a tall blonde so it was a good mix. Slightly annoying having to change condoms but other than that it was superb. The best thing about this booking was how different their pussys were; one was nice and tight and the other was really, really smooth.
The third was shit. One girl just dominated my cock and didn't give me a chance to dictate proceedings while the other done some phony chest stroking.
Basically I think it's a mixed bag, probs best to look for girls who have plenty of experience.