Our stay was good. The room is on the ground floor though, with the door (no window) to an inner court - thus there was no fresh air.
Also, we had some troubles with the checkin as the prev guests checked out too late and then the cleaning staff had to rush to clean it and for us to checkin with 30 mins delay. This led to the room being not clean though. (Can happen but wasn't ideal for us apparently)
Overall it's a good location and okay'ish appartment. Not in a relation to the price though (for what it was it should be at least 15€ a night cheaper).
Bit of a rip-off.