We are a family of 6 staying at Kristian's during our short stay in Madrid of 3 days. Although it was a short visit but the location of his apartment is impeccable as it was near everything that you'll need! It was a stone's throw away from the nearest Metro and a couple of minutes walk away from the liveliest streets including our favourite, San Miguel Market thanks to his recommendation.
Kristian was also really quick to respond to us when we had a slight problem finding the right door to his apartment building as he wasn't available to show us around when we arrived.
All in all, we would definitely stay at Kristian's when we visit Madrid again.