In my humble opinion, it would be the 8820,7720. We bought an 8820 in 1989 that had been operated by a custom operator for 1 year. In the 6 years that we ran it, we had 1 minor stop in all. That was a key that slipped out on the top return elevator shaft. Took us only a short time to fix, and away we went. Our 9600 is more comforable, easier to operate, but in the long run, the 8820 would put in just as many bushels in a season as the 9600.