We enjoyed Maria's place during our stay in Barcelona - we were there for a long stay (20 days) doing some remote work and we specially enjoyed how well located the apartment is. Passeig Sant Joan and Sagrada Familia just a couple of blocs by foot. Plenty of restaurants and supermarkets in the proximity. Metro stop is also very close.
Communication with Maria and her team was great - they had to fix an issue with the curtains in the living room and they sent a person to fix it straight away.
Wifi worked great. My partner and I were working simultaneously having conference calls and we never had any issue.
Apartment has anything you need for a short stay, but if you are planing to stay longer like we did you'll have to buy cleaning products (dishwasher and laundry). Though we appreciate that the place is equiped with those. Having laundry was a savior being there for 20 days.
In terms of furniture and equipment, the apartment could use some renewals - some of the furniture was quite old and a couple of bedside tables were broken. Toilets could also use an upgrade. Kitchen has everything you'll need.
Master bedroom is next to the main avenue, so if you are sensitive to traffic noise you'll have to sleep in the individual bedroom in the other side of the apartment (as I did) or use plugs. Traffic goes from 5-6am to 12pm.
Apartment was pretty clean when we got there but being there for 20 days a deeper cleaning would have been appreciated.