I'm going to get the DX8 for my JD850. The rotary dial will work good for proportional control of for/rev travel & one of the 3pos switches for lft/rht turning. A spring loaded/self center 3pos switch would be ideal for one finger control, but oh well, I'll see what I can do to program that 3pos so it's not too erractic.
It'd be great if there ever was a special excavator radio manufactured with "foot pedals" that would plug into the radio, then you could make that sucker dance.