Excellent location- very easy to get to basically everywhere in BA, including walking everywhere- Recoleta is 10 minutes away, Palermo Soho about 35 minutes, San Telmo a little over an hour. BA is an amazing city to walk around, so take advantage.
Wifi worked fine, no problems at all. The flat is set up very much like a hotel suite. Very clean, tidy and quiet. Friendly doormen too. The only negative was that we had a late afternoon flight and we asked if we could have access until around 3.30pm on the day we left. Lucas wanted to charge us us$30 later check out...and although perfectly in his rights to do so, it seemed...well...just a little bit petty as there was obviously no one coming into the flat after us that day. Apart from that, I would highly recommend this flat.
Oh, and there's a cafe called Delicious on Laprida (look it up) about 5 minutes away that does fantastic breakfasts- way better than the standard cafe fare you find in BA.