I stayed here in a single private room for 2 nights. The room was clean, and the water was hot. I was able to book my Colca Canyon trek through them with no issues & was able to leave my bag there as well. The courtyard area is a very nice place to sit and read. If you're looking for a place to socialize and meet people, this might not be it but if you're looking for a nice, quiet and clean hostel... This would be an excellent choice.
As stated in some other reviews, they do have some staff which speak little to no English but given you are in Peru where the official language is Spanish... I think this is to be expected. Between my efforts with speaking Spanish and their efforts in listening... We were usually able to get the point across.
If I found myself in Arequipa again, I'd come back here.