This is a nice apartment in a new building in a great location in La Boca. It is two blocks away from the Caminito and the touristy area. The apartment has everything you'd need and is pretty comfortable. There aren't really any downsides. It didn't have a microwave when I stayed there but I imagine he'll buy one at some point. There are all kinds of little shops nearby so you'll always be able to find what you need.
The neighborhood feels very safe during the day, however I was warned by a lot of people to be careful at night, but it didn't feel any more dangerous than any other area in the city and I had no issues. Trust your gut and you'll be fine.
the building has a pool on the roof which I didn't use, but some may like that.