Apartment is nicely furnished and spacious for up to 4 people on short trips. It has two proper size bathrooms. Location is good, convenient to a lot of things and central. There is a supermarket just across the plaza which is really helpful with groceries. Also the WiFi works really well. Airconditioning as well and you can have a pleasant stay.
It is quite suitable for short tourist visits, for which the proximity of everything is a big plus.
I hesitate to recommend it for work visits for two reasons: at night it is very noisy, there are lots of people doing "botellon" on the main plaza and is hard to have a quiet night on the main bedroom and 2nd the kitchen, while functional lacks a proper fridge, so you do not have space for frozen stuff. This can be ameliorated by buying whats needed for 2 days or so in the supermarket which is close by so not an issue for tourism, but I believe a bit inconvenient for long stays.
Overall we were well treated by the hosts and would recommend the apartment to people visiting Madrid