I agree the long term dependability of the old stuff is probably better but this unit is undersized for the house and always was.
Besides having an undersized AC unit, I have had to clean the gas burner heat exchanger several times of rust which means that heat exchanger is 30+ years old and on borrowed time.

On a plus side to this system, in 30 years I have had to replace the condenser motor and capacitor twice. I also had to rebuild the drain tray under the evaporator, replace the condensate pump twice, several thermocouples, and the house fan motor once. No single part was more than $90 and was easy to replace. I do not think a new system will be so kind and that is why I hate to see it go, but it is time. Nobody has parts books that include it anymore, so finding parts is problematic when the labels disintegrated years ago.

Even though installing a new one is easy enough, I may pay someone to install it for the extended warranty.

Thank you all again.