We stayed at Denis' place for two weeks this July. The apartment was just as described in the listing. The location is really great! Very central, but you don't feel surrounded by tourists. Which was something we really enjoyed.
The apartment was close to everything we needed, as well as close to the Metro. As other guests have pointed out, there are quite a few stairs to climb in order to get to the apartment, but when you get to the apartment you are above the neighbouring buildings - meaning you do get a bit of air and breeze, as well as quite a view.
We had no issues with the use of electricity as other guests have mentioned. Denis also provided us with a baby cot for our little girl - something that made the stay a lot easier.