This is a great apartment in the middle of a convenient and cool neighborhood — despite being next to the bars and clubs of Plaza Serrano the house itself is very quiet.
We visited during a very hot week (it was 95 farenheit+ most days), but the rooms with air conditioners stayed cool. The stairway and other rooms got very hot during the day, however, so keep that in mind if you're booking for the summer.
Oliver was a very friendly host, and lives nearby to help with any issues.
It's worth remembering, however, that due to currency differences, you might be able to get a better deal booking a hotel in the city and paying with your credit card at the almost-blue rate that Visa, Mastercard etc. now offer instead of booking an AirBNB — booking in advance in dollars ends up being a good deal more expensive.