Long distance buses in Argentina are an economical way to travel around the country. They are not good for those who want to go to the very south Patagonia (Calafate-Ushuaia) as those places are thousands of kms away and the ride is terribly long and tiring, though possible. Calafate-Bariloche is sth attractive to the young people who like adventure . I d rather spend money on air tickets there and save time. But in all the rest of this huge country, buses will help you plan your trip with a very affordable cost and in a pleasant way.
Buses are well equipped, always punctual, they have overnight service, seats are reclinable (120 to 180)and sometimes as comfortable as beds. Sometimes they offer dinner or lunch depending on the time. It is advisable to get the ones that have "business class" or 180 reclinable seats. Almost all companies have a std and a superior ticket. Some companies have std. seats on the upper deck and the superior on the lower. It is important you try to get the latter ones which are only 6 on each bus.
How to make it shorter: If you have time to stay in the country, dont go to the north/south on one go. Make a stop on the way and stay l night 2 days in another city and then resume your trip. That will make you profit from it better, it will be nicer and less tiring. An ideal mid point: stay in the Province of Cordoba. All buses stop there, in different cities but all of them will guarantee an excellent landscape.Tourists have not discovered how beautiful this province is, yet.
Go from Buenos Aires to the whales and penguin areas (Peninsula de Valdez) from there to the Lake district in Bariloche, from Bariloche to the land of good wine (Mendoza) and from Mendoza to the "beautiful" Salta, one of the most impressive landscapes in the country. For the ones who are short of money, the ride between Salta and Posadas (near the Iguazu falls)is possible and the cost is minimum.
Night buses will take you from one place to the other during the night and few hours more sometimes, so what is the sense of being on airports for so long, wasting time coming to Buenos Aires, waiting for the other plane, sometimes spending the whole day on this. Not all air conexions are good,but if they are, welcome.
hope it helps people who are on a budget and have time to visit this country.