Fernando is an excellent host and was very responsive and friendly. I couldn't recommend him more.
The flat's in a good location which is convenient for exploring Madrid in an interesting little neighbourhood next to square with the police station right there.
But there are a couple of things that must be pointed out, especially for older or less mobile folks.
1. It's on the 4th floor with no lift, 85 steps to get the up to the flat, difficult with heavy bags.
2. Inside the apartment, the bedrooms are above the kitchen and lounge, only accessible by a small metal spiral staircase. It turns tightly with no outside guardrail so it's easy to fall off, which we did twice, the second time injuring my knee quite badly. I wouldn't have young kids up there, nor older people. There's a foldout bed in the lounge but that takes up quite a lot of the lounge space.
3. I struggled to get the oven to heat up and washing machine to work properly, even after six days. Fernando's happy to advise