This is a great apartment with a very responsive host and easy check-in and check-out.
Emilio was very helpful and responded quickly to all of our queries, even on a Sunday morning! The location of the apartment is perfect. It's very central so that you can easily walk to lots of tourist places. There are also plenty of nice bars and restaurants very close by. Despite this the apartment is lovely and quiet since it overlooks the Plaza de Oriente which is a quiet pedestrian area. All the action and noise is around the other side of the opera house, where you'll also find the Opera metro stop making it easy to reach more distant parts of town.
The key collection was automated. We arrived at the offices of the company that manages the apartment and entered a code to open the door. We then entered another code into a control panel and a locker popped open with our keys. From there we decided to walk 15 minutes to the apartment (since we'd been sat on a plane for far too long), though the whole process was quick enough we could have asked the taxi driver to wait and take us the rest of the way. Checking out was as easy as leaving the keys in the apartment and pulling the door shut behind us.
The apartment is very well equipped with plenty of storage in the bedrooms and lots of crockery and cutlery in the kitchen. The kitchen also includes lots of extras, such as kitchen paper, cooking oil, even cling film, that are often missing in other rental properties. It has a small hob and a microwave, but no big oven. However, with so many amazing places to eat nearby, why would you want to spend your holiday cooking? The description says that the apartment has no air conditioning, but there were several portable aircon units around the apartment (not that we needed them when we were there). The apartment was nice and warm despite the disappointing temperatures outside.
The photos are very accurate. The only things that confused us were the location of the showers. In one en-suite the shower is behind two mirrored doors, making the photo look a little strange. In the other bedroom, the shower and hand basin are actually in the bedroom itself (hence the matching wallpaper). Only the toilet is in a separate room here.
The apartment is very spacious, clean, and well looked after. We will definitely be staying here again the next time we're in Madrid!