Helena and Alvaro (his brother whom we interacted with), have a fantastic place close to the Plaza Mayor.
Elevator goes from a couple of stairs from entrance to the fourth floor and another floor should be taken stairs. The suite is well renovated and has really nice decorative touches from a 6-foot Audry Hepburn portrait to old maps of Madrid from 18th century, nice beams, race car living room furniture and nice private balcony with seating for 2-4.
The bathroom is a bit small but has all the amenities. The kitchen is well equipped and has a lot of trinkets such as coffee pods for a Nespresso, oils and spices for cooking, jam and honey, and even pasta and biscuits. A bottle of white wine and a six pack of beer were in the fridge.
Alvaro met us when we arrived and showed us around the apartment and provided good tips to what to see and eat around. Try the Jamon and beer deals close by which are awesome.
The rooms are comfortable and A/C works perfectly. Enough blankets and beddings and pillows and towels. Comfortable beds (double bed is made up of two beds so could move around), couches are growing old and might have a dip in the cushions.
There was a TV and audio systems but we didn't use them. WiFi was strong and good connection throughout our stay.
Location was excellent and very close to all the local sights. Lots of stores and eateries around. A gelato store at the main floor in the plaza under the suite can handle any late night cravings.
We will definitely recommend Alvaro's place and will stay here again (if available) when we visit Madrid again to finish visiting the sights we missed.