I agree with several of the other posters. TACA has good inflight service (though the seating is a little tight), good food and drink, and their equipment seems well-maintained. TACA has a reputation for baggage going to the wrong place, but that's generally on routes to destinations with multiple stops or for example to the Bay Islands where the baggage gets put on a smaller plane for the last leg, not so much to Belize.
I've flown TACA, AA and CO many times each to Belize, and on any given day one airline can be really good and the next time not so great.
--Lan Sluder