It was a nice stay - Thanks for that!
It's a great location right next to Parque Retiro. However, the next useful metro station is quite far away, so it's better to take the bus.
The apartment as such was nice and clean. It offers space for six people which is quite nice if you're traveling in a bigger group. However, the furnishing is also a bit minimalistic - don't expect a lot of free space and there are only a couple of chairs for the small dining table - so option to eat there with everyone at the same time.
Room for improvement: We were called twice to confirm the timing of our arrival (two days before and on the day of arrival). Nevertheless there was nobody at the apartment when we arrived and it took more than half an hour until somebody arrived.
There were lots of things broken in the apartment: the door handle upstairs, the curtains on the ground floor, the bathroom door downstairs and some light bulbs. And there is no smoke detector in the whole apartment. These are all things that can be quickly and easily rectified by the owner though.