The space is very comfortable and quiet. It is about 20-25 minute walk to the city center, but there are cool e-scooters all over if you are good with a scooter ride. Uber also worked well for making trips with luggage. The river is very near and offers great play areas for kids as well as a running and walking path for miles and a handful of cafes.
I would highly recommend this apartment.
As for Madrid, it is an awesome town. My only complaint is many place close for the summer and you only find out when you get there and see the sign on the door that it is closed the month. One night I hunted 4 pizza places for my kids and found ALL closed. Another night we made a long trek across town for a TripAdvisor pick to find it and another competitor closed. This was true in Germany and Vienna as well, so just be prepared.