Hi,
I do the 1st AC thing and I've used a follow focus on the DVX100 a number of times.
It works just fine - not as smooth on the pull as for example on a Panavision or Arri unit.
The use of percentages rather than feet or meters is rather a bummer even w/ the conversion table from % to ft. I'm not sure why the guys designed it this way?
I understand, however that to get the most benefit of using a follow focus the camera needs to to shot wide open to reduce the depth of field. It's the usual DP to 1st conversation "You'll get nothing and like it!"