We went from an '02 2366 to a '05 2377 with AFX rotor in '08 and that made a big improvement in tough conditions.  Last year we replaced the factory rock trap beat with a Razor beater and in tough beans that gained us another 30% capacity easily.  In tough beans our 2377 is pretty close to twice the combine our 2366 was and they are supposed to be the same class machine.