Apartment looks small on photos, but in reality it's bigger - standard 'hotel-room-size'. For 2 person would be pretty comfortable for several days visit.
There is beautiful square with many restaurants in front of the apartment and lots of streets with restaurants around it.
Apartment located in the 'heart' of the city - so I didn't take subway or busses. Be aware that from Atocha station you have to go up to the hill.
Any-time check-in with Application from smartphone is very easy and comfortable.