A really great option for Cusco - the location couldn't be better and the staff are lovely, and speak really good English as well as Spanish. I liked the informality and the way I could chat to people in the common areas, but also have my own room, which was really comfortable and like a hotel. It can be a bit noisy as the common areas and rooms are right next to each other, so bring ear plugs. There's no porters or phones in the room to call reception - in that sense it is very much a hostel. The breakfast is really good. It felt very safe as a solo female traveller.
I also highly recommend the hostel's tour organising service, which I used to go to the Sacred Valley and Machu Picchu. They're so helpful and arrange everything for you.