Thank you all for your replies! I'm looking forward to participating more in some interesting topics.
Hey, Joel! Nice to have you here! I've always liked Argentinian trains compared to others down in South America. Argentina and Peru probably have the best systems over there, Chile is OK, Brazil and the other countries have virtually no passenger rail, a big disappointment for me. Hope your trains still keep running well, also heard that they have heavy competetition from luxury buses. You know, in America, the trains are always more expensive than uses, in Argentina it's the opposite AKAIK.
Well, we used to have one of the greatest networks in the whole world. But (as always happened), governments screwed it all up. Just to clarify what I'm saying, this map could help (It's a little bit heavy, sorry):
It is all written in Spanish, but the image speaks for itself. In light blue are marked the lines that still offer some kind of service. Almost none of them operates daily, and travel times have grew dramatically in the last 20 years. In pink, some regional services that run daily but considering the distances they should have some more frequencies. With violet edges, tourist/heritage trains. Again, none operates daily and even there, there have been withdrawals (the Old Patagonian Express from Ing. Jacobacci to Esquel - which was one of the last steam operated lines in the world - has been cut in three silly parts, the same with the "Train to the Clouds" - it was a REAL service to Antofagasta, a Chilean city by the Pacific. Now it is only a roundtrip to Polvorilla's Viaduct, the highest point in the line, costing around 120 dollars each...
).
And finally in grey and yellow, lines that now have no passenger traffic (in yellow there are some recent withdrawals), some still have freight, but travel speeds are just a joke. A lot of these lines have now disappeared, even in important cities. And yes, everything is dominated by "luxury" double decker buses. There are departures 24 hours a day to almost every city in the country, and of course there's a lot of traffic between cities, not passing thru Buenos Aires. I just hate them, our routes/highways sistem differs a lot from the one you have, there's almost none "Interstate-like" highway here - only two lane routes, one outbound and another inbound. Of course, this makes travelling by bus a very very dangerous activity, but people seem to accept it, given the fact that there are almost no trains, and travelling by plane is barely impossible (and our network sucks - for example, if you need to fly from La Rioja to Formosa, you will have to make a connection in... Buenos Aires). Besides, trains are really abandoned, only some routes preserve sensible rolling stock (none younger than 30 years). Train is always cheaper but getting a ticket for the most popular routes may be difficult, and the stereotype of the train being "the transport of the poor, thieves, beggars and stuff" has been installed in the last 20 years (the most of the important lines were closed in 1993).
Anyway, a lot of interesting rides are still possible, so whenever you want you may come and try it out!
I'll later post some images and reports of recent trips i've made here, so you may see how are things going down here. Sorry for the long presentation - felt I needed to explain the situation a little bit.
Again, thanks for the greetings!