That friend of mine did not complain about breathing problems in Bolivia but he is quite experienced with those environments as he has also travelled in Peru and Ecuador a lot, including some towns at over 4000m height. He did say Bolivia was more authentic than most other South American countries, probably he means it is less globalised and less internationalised than the other countries who get tourists and expats from all over the world. Bolivia indeed seems 'less travelled' than the other S.American countries. Paraguay may be the same though, as there's not too many travellers going there.
Doesn't Montivideo also have a soccer team called River Plate, just like Buenos Aires have? Probably a reference to the same water that seperates Uruguay from Argentina?