My girlfriend and I stayed here for a whole month. The apartment is newly renovated, clean and in an amazing location. The biggest problem is noise.
The apartment is on the first floor and it has old-style windows. The windows don't block out any noise. There is a bar immediately below the apartment that isn't very noisy but might have people hanging around outside talking on Fridays and Saturdays. This wasn't the biggest problem though. The hostel across the street has a bar that is open late (1-2am) every day and you can hear the music and the people talking easily. Then at 7:30am on most weekdays workmen come and load up their trucks in the street right below the apartment and appear to be having a contest to see who can drop a pallet from the highest point possible. We wore earplugs every night but still had trouble falling asleep and were always woken up in the morning.
If you can handle the noise, the apartment is in a great location. You can walk 10 minutes to Plaza Catalunya, 15 minutes to La Rambla and 2 minutes to Plaza Universidad where the airport bus stops and where there is a metro. We walked almost everywhere while we were in Barcelona because the apartment was in such a central location.
The WiFi was excellent. 30 Mbps up and down.
The apartment is in great condition with everything new. There's a TV, couch and a big dining room table. The fridge is spacious and there's a full stove and oven. The kitchen is decently stocked however we noticed there wasn't everything we needed for staying long term.
Gerard is very nice and WhatsApp'd us things to do the entire time we were there. He responded promptly to all our requests such as asking for tupperware that was delivered within 3 hours!