I think every shower I've seen in Europe -- with the exception of one hostel in Lisbon -- has detachable shower head. This really surprised me when I first arrived. It's out of habit that I always keep the shower head on the wall even though I can take this one off. I don't see how it's that useful.
I told this to my German housemate who shared a bathroom with me and she was very surprised. It's so useful, she said. Indeed sometimes after she used the shower, the shower head would be resting on side of the shower stall the instead of put back on the holder. She does use it all the time.
What also bothers a lot of students here are showers without a shower curtain or glass separating the shower stall from the rest of the bathroom. Thankfully I don't have this problem because I have a shower curtain.