This place is great and our entire group loved it. It is modern, stylish, very clean and extremely comfortable for large groups. We were 8 people in total; 4 adults and 4 kids ages 9 to 13 and we fit perfectly.
It is extremely well insulated from the outside and other units. We visited in the winter and the flat was always warm and cozy. As others have stated, the water heater only has capacity for 2 to 3 short hot showers, but we spaced them out allowing time for the water to re-heat and so we didn't experience any issues with this once we adapted our routine.
Although the metro system was shut down due to the strike, there is a station very close by, so the location is very convenient. The host is also very responsive and proactively checks in with you to make sure things are going well. That was a nice touch.
Overall, we loved it and would happily stay there again.