Stayed two nights with friend at June 2013. Anyone who has been at hostel knows what to expect and Why Not does not fail to meet the expectations.
We stayed in 2 bed private room at price 250 UAH/night booked by email. Bed was ok, room reasonable sized and was equiped with aircon :) During our visit hostel was very quiet, about 5 other quests I think. There is one small common room + kitchen with washing machine. Reception staff was freindly and I think reception was manned 24hours per day, or at least somebody was sleeping on the couch at night :)
Location is quite close to city center but could be better as there is about 15mins walk to the main street.
In short: nothing special but no problems either.