If you are at the Park Hyatt, I think you want to make sure you are not in the contemporary wing, which is pretty much like any other Park Hyatt in Europe (think PH Zurich). The best part of the property is the link to the old Palacio Duhau. Service is OK, even taking into account the slightly disconcerting lecture about the nasties in BA that can befall unsuspecting tourists (which I have never experienced).