Excellent location, only a 2-minute walk to the Iracema Beach. The staff was helpful. The rooms and beds were cozy enough. Breakfast had quite a large variety of food served. The common area was something that I really enjoyed...3 or 4 hammocks available, a large screen TV. It's pretty much a good place to talk to your hostelmates.
I stayed in Local Hostel Manaus only for 1 night, after an Amazon trip, during the World Cup period. From my short stay there, I can say that this is an excellent hostel to stay in Manaus. It's very clean, and has a nice common area. Most importantly, it's very, very strategically located. Only 10 meters from the city center!
I stayed at Rockn Hostel for 2 nights during the World cup. The hostel itself is nice. The beds, showers, and the TV room were all comfortable. The downside was mainly the value for money. The cost of the hostel was very much overpriced during the period I stayed there. It was around 100USD per night for a bed. (But to be fair other hostels were also overpriced at that range) Also the location is pretty steep. The way up to the hostel is a tiring, 20-minute walk from the Savassi area.
I went to Curitiba during the World Cup period. The hostel had a very helpful staff, which helped me to set my itinerary. They also organized a good night out for churrascaria for us. I felt that the staff did a very good job overall. The hostel was around a 15-20 minute walk from one of the city centers (Centro Historico), which have a few bars. As is the case with most of the hostels, I thought the price-increase too much (around 3x) during the period where they had games in Curitiba.
I only stayed at Foz do Iguacu for 1 day - 1 night. What I liked most about Hostel Bambu was the helpfulness of the staff. The hostel manager immensely helped in managing me to squeeze in a visit to the Iguassu Falls (helicopter ride, boat ride, and the walk up) and a special tour at the Itaipu Hydro Power Plant. In order for me to make all those arrangements promptly, he arranged for a car to take me to those places and a return trip, all for a very decent price. I can't thank him enough!