Yes, the advantage of my low-option airplane is that it integrates better with the G600. Since I don't have altitude select, I can just use the alerter built into the G600, and I also didn't need to keep the old VSI.
So all my airplane really does is pitch hold (set manually using the control wheel steering button) and IAS hold, which actually works fairly well. Having VS and altitude select would be really nice, though.
I think at some point, I'll probably do the autopilot.
If you already have Hartzells, the overhaul isn't all that much. And I don't think you'd see much gain in performance with the MT props, but I could be wrong. They would probably be quieter, though.