I tried it recently on the Rocket Classic but not our bikes.
You should get used to it quite quickly.
Normally you change gear without thinking about it but I found myself thinking about 'am I pushing with my toe or heel?' for the first 10 minutes of riding.
It should soon come to you.
I got quite used to it actually but already knew the price of the kit over here for our bikes and knew I wouldn't be getting it.
Too expensive for what it is over here.
Good luck