Thanks. The business class fares on AV seem reasonable and this might be a good reason to chose them over LA.
I assume no difference in terms of safety (maintenance, pilot training, etc.)?
I had the same questions when I booked last year for my flights in February this year. As the flights between those cities are very expensive it was actually cheaper to book a business class ticket on Avianca-Taca instead of a Y ticket on LA and Avianca-Taca.
My two flights were on time and I had no issues with the service received on the ground or in the air. The staff were all friendly and priority was always given to C class passengers. Food was a cold appetizer which was quite good and the seats are comfortable too.
My only worry was that it seems that Avianca-Taca pilots are not trained for all weather scenarios at Cusco airport. I read somewhere that they cannot fly to Cusco if it is foggy or bad weather. Even Star Peru and Peruvian cannot depart/land then. So it is not only an issue for Avianca-Taca.
However both times I had good weather and my flights were on time. Also as Avianca-Taca has less flights between those cities there might not be many alternatives for you if there is bad weather etc. Apparently LAN seems to be the only airline which can still land and depart if weather is not that great.
However I felt that the pilots did a good job and spoke good English during the announcements and therefore I have no issues recommending them.