The place is very central and close to many of the main attractions - we walked almost everywhere in Madrid for 3 days and the metro tickets were a waste :). The street is also full of restaurants and close to a supermarket, so it felt lively and safe in the evening.
The apartment is also very spacious and has everything you would need for a short stay, including kitchenware if you want to do something quick at home and bio bathroom products, which we really liked.
We recommend this apartment and gave it 4* - the place was not warm enough for December (at least for us) and sometimes a bit smelly. However, we really enjoyed our stay in Madrid and would return to this apartment!