I've only flown Aerolineas twice (MDZ - AEP) and had decent luck both times with on-time arrivals and no lost luggage. But I've heard a lot of horror stories especially with international flights. But for these there are enough alternatives out of EZE that you should be able to avoid them entirely.

There is an alternative domestically, at least on some routes: LAN. They started up operations in Argentina a few years ago and have been slowly expanding their route network. For domestic service they're nothing special but they are more reliable than Aerolineas, so I'd check with them first.