I've been to one out side of Koln/Cologne- Samya and 2 near Frankfurt - Mainhattan and Palace.
I prefer going during the day when things are a bit slower, give you a bit more time to explore the facilities, relax rather than having to wait for a room in the evening. Either way, the 60-80 entrance fee covers most things, minus actual massages, time with the ladies, and in some cases beer. was kinda shocked at first, but you quickly figure out who might be a good time and who doesn't fit your preferences.