Craz,
I mostly agree with you on the service issue and that if it came down to buying tickets I don't see what TACA has to offer over the other legacy airlines. I'd rather collect AA or UA miles if I can I guess and get the same drab service.
I also agree that Avianca provides nice service and is worth the effort. I highly recommend that anyone passing through Bogota in the future take a day to stop in the city and check it out. Can be done easily.