I've stayed in other cities but mainly lived in Rosario and BsAs. I've also travelled through the country by Bus. My ass, it's a still sore.
In my past world travel adventures, I visited London England. When I mention this to English people, they often say "ah, but that's not really england is it?" What they're getting at is that the biggest major city isn't the best representation of a country since... it's a big city like so many in the world with big city problems and a cosmopolitan population.
This is the same thing I'd say about BsAs in comparison to the rest of Argentina. Most regions are quite different from each other and everywhere is similar in certain respects. They all love mate, beef, wine, family for instance. Outside of BsAs they all hate BsAs.
Rosario was great to live in but the weather was crazy. Thunderstorms like the end of the world was coming and even more humid than BsAs if that's possible. Fantastic looking girls and nightlife is excellent if you know where it happens. English isn't too hard to find and I found the people there very friendly. I'm not sure if it's all that much cheaper than BsAs to live in as the price of housing is going up like crazy. If you like sailing or watersports, this is the place to live since it's on the muddy river. Nice beaches draw lots of BsAs tourists.
Cordoba is another city I spent some time in. Even better looking girls and lots of nightlife if you're under 30. It's a young town filled with university students like Rosario but even more so. Less english here and I found it more gritty overall. If you like churches, you'll be in heaven. Seems cheaper than Rosario & BsAs and has the advantage of nearby small towns and sierra landscapes for hiking.
One of my favorites is Salta, towards Bolivia in the north. Heavy native population and I think it's considered one of the poorer major cities in Argentina. Seemed cheap to me and I found the best steaks here. Also really enjoyed the downtown just for walking around. Lack of Spanish is a problem. Lots of nightlife especially live music. Interesting surrounding landscapes. Smoking hot in summer.
Going south... lots of nothing with the occasional medium or large city. Even more expensive that BsAs and less english. Nightlife is many smaller cities is not happening. period.
Final note: if you're in BsAs and enjoy it, stay there for awhile. It's an amazing city and there's so much to explore there if you're willing to leave the tourist areas of the centro. The portenos also have their own culture which is fun to hate (in a way). It can be cheap to live there if you find the right situation. I could've had a room for 300 pesos a month if I was willing to take trains everyday, which I wasn't.