Very nice and practical apartment - it has everything you need leaving plenty of space for clothes, groceries etc.
My son used the sofabed which was comfy. Nice beddings and towels. Communication and check-in were smooth and clear, and practical instructions were given for both the building/apartment as well as getting around Madrid.
We used the gym several times, it’s on the older side but clean and functional, with plenty of machines and benches/free weights. (incl. ellipticals and bikes - no treadmill though).
Transport to the city center is easy by metro, but we also walked a few times.