We stayed at Hostal Wara Wara for one night at the end of June, and were pleased with our stay. We were picked up at Cusco's airport by a driver that HWW had arranged for us, and were able to check in early. HWW's manager (apologies, can't remember his name) gave us a map of the city and was happy to provide sightseeing and restaurant recommendations to us. He also helped us arrange for a driver to take us to the Peru Rail station the next morning.
Location is fantastic and very central -- probably a 5-10 minute walk to Plaza del Armas (which is the main, touristy center of the city). HWW is up on a hill, so getting to the city center required walking down a long flight of stairs, which, coupled with altitude sickness, may not be the best combo, but we had no problems aside from shortness of breath. The view of Cusco from HWW's balcony is amazing! Beautiful panorama of the city.
We stayed in their double twin bed room. The room was small but clean, and towels and a bar of soap were provided. HWW has free wifi, and the signal strength was so-so. The room had a private ensuite bathroom. The only real issue we had was with hot water, which was erratic at times, and would sometimes run out after a few minutes of showering. The sink has no hot water function. The room was not heated and was pretty cold in the morning and evening, though the alpaca blankets that were provided were nice and warm!