Gustavo's apartment is in a great location and the photos are a true reflection of what to expect.
I didn't meet Gus however communication was great, friendly and quick. Roberto who I met upon check in and check out was also friendly - however we didn't have a big chat as I am unable to speak Spanish.
Despite the comfort and good location of the apartment I just found it too noisy .. I didn't sleep well at all the week I stayed. I found the traffic very loud, constant alarms going off and could even hear the beeping sound the elevator makes constantly.
I wore earplugs to bed and was still bothered by the noise.
On another note, I would have found it invaluable if there was some written info available...that is, where the closest subte station was, grocery store, etc .. a map perhaps of the local area. Arriving at night and solo in a new city it would be a helpful head start.
On the wifi front I found it painfully slow at times, better at other times but certainly never fast.
Don't miss Recoleta Cemetery - it's fabulous - like an open air art gallery - and walking distance from the apartment. If you're into street art I highly recommend the walking tour with BA Street Art Tours - saw some beautiful art and met some great people.
As for the apartment, I'm sorry, I wouldn't stay again.