Advent is a newer low cost chinese addition to the RV market. Very few OEM's use Advent. They do not have a track record yet. BUT, I would go the Advent route due to the age of your RV and the fact that Advent makes an adapter kit for your Carrier. Doug
PS, Carrier exited the RV market after a few years because the units were junk
Can I replace a Carrier upper unit with an Advent upper unit?
If all other components of the Carrier system are functional, the ACCARKIT Carrier interface kit allows the Advent upper AC unit to connect to the existing Carrier relay box.