The location is very good. It is a residential area. There are a number of supermarkets, stores and a bank within a few blocks, and the metro station is three blocks away (Pinar de Chamartín). Two stations from Pinar de Chamartín you can find one of the big train stations (Chamartín), with long- and short-distance trains and more metro options. You will find the location is well connected with the rest of the city.
The room is about 3.2x3m, minus 2x0.6m in the form of a wardrobe which is spacious enough to put your clothes and luggage in. It is well furnished, and has a large window which is good for ventilation. The room has its own little fridge, which is where you will store your groceries, and you will also have space in one of the cupboards in the kitchen.
The kitchen is large and very well equipped, with an oven, cooking tops a microwave and a dishwasher. You can use the dishes, cutlery and glasses. There is a washing machine and you can hang your clothes right outside the kitchen window, where they are protected from the rain and pigeons.
The bathroom was shared between two rooms, which is fine, as it is unlikely that the two will need it at the same time. It is small but functional. The shower space was OK for me, but I am about average in height and light-middleweight for a guy. If you are a taller person (thinking 6ft and above), the space may be a bit restrictive. Also, if you are either overweight or just have a bigger frame, you may not be able to get in. If you have any mobility issues, you will have a hard time having a shower. If any of the above apply to you, I suggest you ask the owner first to see if you can work something out.
The shower temperature regulation worked great, the underlying system is a heater that does not run out of hot water. This is something you appreciate if you experienced hot-water issues elsewhere.
Communication with the owner was very good, she replied quickly and was always very polite and helpful.
During the summer you can register to use the swimming pool for an additional fee. Had I had stayed longer into the season, I would have done so.