Location amazing, staff really helpful, except for one night, when a guy brought back to the room we shared with 16 people a 40 year old woman from London, and the reception said they couldn't do anything, even though it's a policy not to bring strangers in. 6 of us left the room at 3AM, it was just too awkward. This is bad for the hostel's security, in Barcelona the same thing happened, a tourist hooked up with a local and when we woke up we realized she stole from everyone in the room.
This hostel is more of a hotel. It is located quite far from the city center in a weird neighborhood, so you have to take the subway to get near Grote Markt. Nevertheless, it is very modern and extremely big, the rooms have TVs, they are clean, with a private bathroom, but without lookers. There are so many people that come and go, that it is a little difficult to make contact with someone.
I stayed at this hostel for 2 nights and it was amazing. It is quite close to the bus station, I'd say a 15 min walk. The staff was very welcoming and helpful, the even organized and booked my day trip to Northern Ireland (Giant's Causeway, Carrick-a-Rede Rope Bridge, etc.) and also the black taxi tour. Every morning they cooked a free English breakfast to everyone, which is the nicest way to start the day! They don't have a lot of bathrooms, but the ones they have are clean and modern.
This hostel has the best location in Zurich. It is not as clean and as modern as I would expect it to be for that price, but I guess everything in Switzerland is expensive. The staff didn't really organize anything for the guests (I don't remember seeing them a lot), so the atmosphere was kind of boring, and if you want to go out or sightseeing, you're going to have to be ready to organize everything on your own. Also, the facilities and the rooms were quite dirty.
This hostel is located in the heart of the city. The common area is really beautiful and cozy, and the rooms are quite normal, clean, with lockers and beds. There isn't any kind of breakfast included in the price, which is surprising, as it is quite expensive to stay there, even when you're sharing your room with 6 people. Also, you had to pay to use their computer. There weren't a lot of young people staying there, so the atmosphere was more relaxed and quiet. Overall, it's a nice place.