We had a wonderful stay at Sky of Madrid Penthouse. It was a treat after spending a few nights in a tiny hotel room in Barcelona. We get to spread out and enjoy some time in the living room or the terrace after a long day of walking or coming back in between for a break before dinner time (because the location is so strategic!).
Ludovic is very a responsive host. He answered all my questions (there were many :-P) prior to my stay and continued to do so during my stay, checking-in to make sure I had everything I need. Ludovic is also very knowledgeable about Madrid and is genuine and sincere when asked about his opinions about places and restaurant options. We like all his recommendations - the restaurants, Flamenco, groceries (panic bakery and cheese shop) - we enjoyed all of them.
We just wished we had more time. The terrace was the highlight of the stay as everyone would agree here. Another great thing is the apartment was quiet despite its strategic location. I slept really well and felt relax, like at home.