The good: fantastic location for exploring, nice apartment with comfortable beds - the photos don't do it justice. José María was nice enough to buy a travel crib for our baby to sleep in.
The bad: it's loud. It's on the first floor, with a square at the back where the bedrooms are, and the boulevard at the front by the living room. The square has a glass disposal bin with constant smashing glass. There was a DJ there one night (during semana grande, at the end of our stay) that completely prevented our baby from sleeping. There are daily street performers on the boulevard (and a parade during semana grande), though this doesn't affect sleep. Lastly there is a garage door directly below one of the bedrooms that makes a lot of noise every time it opens and closes. I of course expect some noise while staying in such a central location, but this was unrelenting and made it difficult to relax and unwind in the apartment, moreso than any other central location we've ever stayed in.