The location of Hostal Balkonis is very convenient; there's metro stop right next to the hotel and it's also within walking distance of most of the main attractions and you can also find great restaurants within 1 km. There's a mini market around the corner and also a restaurant that serves food until the late hours. The staff was very helpful and friendly from the beginning, and they gave us great tips of how to get to the airport and what to see in the city.
The room itself is very basic. We had a double room with private bathroom, which was located on the first floor and had a small balcony facing the street. The biggest minus for us was that it was super cold in the room. We visited in April, and the bed had only a sheet and a blanket, so we were freezing every night. I guess it's the opposite during the summer and one will be sweating in there. The shower could've also had a shower curtain to avoid the wet bathroom floor.
All in all, a decent spot to stay but on a general level the quality doesn't meet the price. I know it's Barcelona and all, everything's on the expensive side but like in many European hotels and especially hostels, the prices have gone crazy compared to quality.