The fast-paced group problem solving is quite enjoyable, although I still think it's not worth the 20 € / person they usually ask.
Both of the rooms I've done had a hints system so a staff member overseeing the game through cameras could send a hint any time we dropped significantly behind schedule.
One of them had a two-room system where you had to solve the first room to get to the second room, and in the second room I believe one or two of the locks had been unlocked ahead of time manually by a staff member, based on how quickly we solved the first room.
Of course every time anybody takes the challenge you acquire more data, and keeping an eye on the emerging patterns must be absolutely critical to engineer an enjoyable challenge for the maximum number of different people. Metrics!