I flew a "mileage run"/short weekend trip JFK-LAX (UA PS) connecting to TACA LAX-SAL-MGA and return over Memorial Day weekend, in Y. TACA pleasantly surprised me - the flights were all on time, the long flights included free beer and a meal (maybe a little better than a typical pre-deregulation meal in Y, but it's been long enough that I won't guarantee that statement - in any case the meals hit the spot). SAL was very convenient for the plane changes, with a modern feeling and a variety of shops & food options (most, if not all, accepted US$).

I would happily fly them again.

P.S. - I tried to see if they would sell upgrades to Clase Ejecutiva on the return, but the GA said no - I think they don't sell upgrades, but my Spanish is weak enough that maybe they were full in C.E. on that flight.