Stayed at Oliver's for 2 nights in April 2014. If I had to summarize my stay in one phrase: it's a five star experience! I cannot find a single thing that was below a five star level.
As a host he was truly attentive. He took care of things he did not need too. We were watching a Real Madrid game on the night of our arrival. Olivier received our tickets in the mail, then he met us at a garage to hand us the tickets because we were running late.
His apartment was amazing, the cleanest and most comfortable bed. We had a light breakfast with coffee ready everyday. We had out own private bathroom in the room! All that with an amazing location with a view of Plaza Mayor!!
I highly recommended staying at his place. I would defiantly stat there again if I am in Madrid.