This was the first time that I rented, through airbnb, a bedroom (instead of the whole house). And it was a very nice experience, once we had a private bathroom and a private entrance (which gave us the positive impression of being apart of the house). The flat is not near the centre of Madrid, but is well located, near cafés, bars, restaurants and a metro station. The only remark that I would make (and that maybe is not a problem to others) is that the door of the bathroom is not a "real" door (I mean, it's more like a glass door, similar to those used in showers, which means that it has transparence and it didn't provided, at least to me, the feeling of being in another room, when I walked from the bedroom to the bathroom). If you are not a shy person or if you are travelling alone, it is not a problem at all, because all the rest was super!