Mercure Hotel Berlin City is well located, 950m from Berlin HBF (central station) and with a tram stop right out front. There are also plenty of restaurants within 10 - 15 min walk.
The hotel is clean, and our room had adequate, albeit basic facilities, other than a fridge. The restaurant was more than happy to provide ice on request though.
Service is okay, though I had to go down to reception to collect a firmer pillow, rather than it being brought to me.
The most annoying issue I had was the air conditioning, which functions differently than what i am used to. It shuts off entirely once the air temperature outside reaches the setting in the room. The room then gradually warms up to the point where I woke up on 2 of 4 nights feeling that I was suffocating.
Normally, air conditioning kicks back in once the room warms up, but this one does not turn back on. The front desk were aware of this issue and offered to unlock the window for us. Whilst this helps, I shouldn't have to get up during the night to open the window.
The mattresses also need to be rotated. I felt like my feet were higher than my body.
I loved Berlin and will come back to this city again, though I'll stay somewhere else next time. Mercure Hotel Berlin City is average at best.