Some are nice, and some SUCK! When I was in New Zealand I stayed at four different ones, which ranged from pretty nice, to pretty crappy. One I stayed at, they didn't bother to clean the damn room before we got in there, and it was really dirty. The bathroom was nasty, there were old apple cores and chip bags on the floor, and other misc garbage. I finally told them I wanted a new room the second night, because the first one was foul.
This other one I stayed at was nice, but it was like someones house. I think it was at one time, but the owners made it into a hostel to make some cash. It was pretty cozy, and had a nice living room area. The weird thing was, the bathroom was one big shower. One person at a time of course, but you go in and the whole damn thing was tiled, and had a drain in the middle. It was like a massive shower with a toilet and a sink. You just stood there in this big room with the sink and toilet, and it had a shower head coming out of the wall. Weird.