I bought the 48 hour pass but only used one day. I was able to fit in 2 of the 3 routes. The City Tour route is deceptive. Most of what I saw was walkable but only learned that after the fact. The bus can only travel through major roads. As with most of these bus tours, it is a good way to get your bearings right from the start.

The tour was decent but the audio lacked details and information. Also I got off at a stop and asked if there would be another bus coming to pick up and he said yes there are 2. I was at the stop 30 minutes early and when the bus arrived the driver said no the tours done. I had to pay 20 euro to get back to my hotel.

Basically a good thing. The waiting time for the main line is very short (half an hour), for the other two lines you have to wait about 1 hour. But you can manage all three lines within 24 hours. Some of the employees do not speak German very well, so information was provided via the automatic announcement. But the staff was very friendly and tried hard.