Apartment was exactly as expected and location couldn't be better!
However, be aware that due to it location (Malasaña is a very animated neighbourhood), at night, it can be relatively noisy due to street noise.
We had to do a self check in (only due to a late flight delay) but this was quite easy to do and clear.
The place where the keys were left was relatively easy to find; however, the keys were left in the night shop which was not clearly mentioned in the communication we received (this left a us wondering during quite a few minutes).
All in all the place is ideal for two couple going on holiday together.