Thanks for the reply, Gaucho.

I used Google Earth to look at Recoleta and Palermo, but contrary to my expectations it looked very busy with lots of trafffic on the streets and a bit run down. Not leafy, quiet and upscale. Am I missing something? I thought that especially Recoleta was like Beverly Hills, LA.
Are there no leafy, quiet streets or squares in BA with a nice hotel adjacent?
Something like Condesa in Mexico City or Miraflores in Lima.