We travelled with a colleague and stayed in the apartment for 2 nights. We didn’t see Irene at check-in but she arranged the representative to be present in the apartment and check-in went very smoothly. My colleague and I even got two sets of keys as we wanted to be independent from each other.
Apartment is small but well-equipped and location is perfect. La Latina metro station is less than 10 minutes walk.
You can find some cooking ingredients in the kitchen (oil, sugar, coffee, pasta, rice, etc) and this is very convenient and thoughtful.
Heaters work properly and it’s not cold inside (we stayed at the beginning of December); however, floor is cold (especially in the kitchen) and if you are not comfortable about it, take your slippers with you :)
I find this apartment convenient for company of friends or a couple but not for two couples who plan to have a romantic trip to Madrid as doors between the rooms look more like dividers and there is no door between the kitchen and the rest of the apartment.