I think the problem with a rotary drive is that the drive unit was often fitted by the factory under the drainage channel by the bottom of the pedestal base. This meant the drive unit axle was exposed to water unnecessarily as it is possible to offset it enough to be away from the drainage channel, or to protect it with a shield of some sort.
I have gone down the wheel drive route as it involves minimal construction effort and we mainly use the autopilot when motoring anyway. The work is not that complex – fit the control unit and compass at the chart table, use the factory fitted power wiring, fit a data cable to the pedestal then install the control head and wheel drive with power and data in the pedestal.
If the wheel drive is insufficient (almost certain is for even moderate wind sailing) at some point the future we’ll upgrade the control unit and fit a hydraulic ram to the quadrant.