I chose this hotel based on a recommendation from the conference organisers. It was close to the conference venue (Palau de Congressos de Catalunya is just 2 subway stops from there), but not so close to the city centre.
As written in other reviews, the hotel looks somehow old-fashioned from outside, but inside it's fresh, modern, nice, and with a new (small) swimming pool on the roof.
After reading the reviews at TripAdvisor, I asked for not having the room at 1st (smoking) floor. We were lucky to get a room at the 2nd (non-smoking) floor.
The room was pretty small and dark with heavy curtains, but clean and quiet. Even though we had windows towards the street, we did not hear any noise.
The beds are highly comfortable. The bathroom is really nice with lots of amenities (shampoo, tissues, shower cap, even toothbrush etc.) which were regularly replenished. (The only small thing I missed were cotton swabs.)
Breakfast was very good with variety of (local) products. (Again, only one very very minor complain - it took time to get a hot water for tea, the coffee/tea machine was somehow slow.)
Staff in the hotel is very nice. Every morning, they asked us how we slept, and they were very helpful with all our questions and special requests (e.g. leaving bags in storage room after check-out, sending out postcards, etc.).
Wifi works well.
Tip: If you go from the subway, you do not need to go around but it's possible to go through a small park and then throughout a passageway to the hotel. It's much shorter.