I'd assumed for most of my adult life that I'd end up living in Brasil, but (unfortunately) ended up on the wrong side of the border in Iguazú. I'd never even considered Argentina prior to finding myself living here! So no preconceptions about Argentina, but.....
Having then lived for 2 years in Iguazú, I had plenty of preconceptions of Porteños. The rest of Argentina pretty much despises them and considers them rude, ignorant, snooty, dishonest and psychotic.
I can't say as I've noticed much of a difference between Misioneros and Porteños to be honest....they're ALL rude, ignorant, snooty, dishonest and psychotic!
And as I'm pretty much trapped here for the rest of my life I'm adopting the philosophy of '
if you can't beat them, join them.'