The location of the hotel is perfect in Barcelona! You have the pedestrian street literally around the corner and La Rambla another hundred meters away. Placa de Catalunya (Barcelona's absolute center) is a few hundred meters away. This is where the airport buses (Aerobus) stop, which is very convenient. It's also around Catalunya you will find the best shopping.
The standard of the apartments is superb, with a good kitchen, washing machine etc. The beds are comfortable. The apartment is surprisingly quiet, given the central location. A slight weakness is that there are no blackout curtains for the windows. The rooftop pool is nice and definitely worth a visit.
One possible weakness is that the hotel lacks a reception desk. It has an office where the staff works, which is open during office hours. If it is a hotel experience you are looking for, then you will be disappointed. However, if you want an excellent base for discovering Barcelona, this is perfect!