Isabel was very forgiving as we were running late for check in. The apartment is in a great location, but be aware that you have to carry your bags up several flights of stairs. The bed isn't exactly a mattress, but it was still comfortable. The heat worked well and the kitchen was well stocked, just be aware that the space is a bit smaller than it looks in the pictures.
Overall it was a great value for what we needed and we're happy with our stay in Madrid.