Pay papa… the girl assigned will grab your hand. Ignore her completely. Take a few steps towards the women sitting and take a long look at which ones you like. I’ve even chosen the initial one that went up to me before a couple times (funny enough). But, when I go I want to choose from all the girls. That’s one of the main points of going.
In terms of how rushed it is, it will definitely depend on the time you enter, the girl, and the mileage that may vary. You can get some very good sessions, or some very rushed ones here. It’s not for everyone. Embrace the experience when you go, and if I’m showering next to you … let me know you left your session with absolutely no regrets.