Compared to Brits, Argentines hardly drink at all.
Aside from the teenagers from the suburbs, you almost never see a drunk Argentine.
I would say expats or visitors from Blighty outdrink locals by at least 4 to one, and if you are in a non-expat bar, the only time you hear loud drunks, they have an english accent.
It is not uncommon at all for Argentines to drink a few bottles of wine for the table, but seldom will they order more than one or two cocktails in an entire evening, and the idea of standing endless pints of beer is pretty much unheard of here.
I have never once seen anyone, old, young, male, or female, puking in the street.
Nothing like these quaint pictures from Cardiff-
http://www.pbase.com/maciekda/cardiff_st_mary_street_zone
So expect an entirely different nightlife experience. Unless you only go to expat bars- me, I have never been to any of them, so I cant speak to that.
But normal Porteno nightlife is pretty civilized, although it starts very late.
Restaurants are often crowded, with one hour waits to be seated, at one in the morning.