We spent 2 nights in Eva's apartment. The apartment was awesome, fully equipped and had more than enough place for 6 people. Everything was new and nice and big plus is that it has two bathrooms. The only disadvantage is a hot water heater (boiler) because when 6 people need to take a shower, hot water can run out and you have to wait until water is warmed up enough.
Location is also not bad. The station of underground is only 5 mins on foot and 6 stations away from Plaza de Espaňa (the main street Gran Vía starts here). We were totaly satisfied and recommend this accomodation.