My husband and I enjoyed our 8-day stay in this very centrally-located and reasonably spacious apartment.
Many of Madrid's attractions are within easy walking distance, and there are also two metro stations extremely close by. So it offers wonderfully easy access to the whole of the city.
The apartment was clean when we arrived, and in general we found it quite comfortable.
I personally, though, thought the design of the kitchen area a bit crazy since there's no draining board at all and it's also difficult to use the 'breakfast bar' because this is an extension of the work-surface with fully built-in appliances underneath that make it impossible to tuck your legs in when sitting on the high bar-stoool style chairs. A conventional table and chairs would be much more user-friendly.
We found the kitchen area as a whole sparsely equipped, but since we spent most of our days out and about this wasn't an enormous problem for us. It'd be good, though, if the cutlery drawer included a couple of tea spoons (not just table spoons), and if some coffee cups and saucers were also made available. (Having four large tea mugs is great, but the size of these isn't invariably appropriate.)
On the other hand it was good to find that an electric kettle was provided (not always the case in Spanish apartments).
The bed was exceptionally comfortable, being firm and made up with a wonderful duvet that kept us really toasty during a couple of chilly October nights. Fortunately the weather was milder during most of our stay, since although an air conditioning unit and a couple of fans were provided we didn't discover any heating equipment. If there is a heating system at all, its workings really ought to be explained to guests.
The owner's assistant who met us on arrival was, though, very pleasant and friendly. And the bottle of wine she greeted us with was a very kind gesture.
On the whole it was a very good place to stay.