Hi,
I have the follow me tandem and use it on both my tourer and my hybrid although the latter is only for towing the empty bike it's heavy but very stable.
Seren didn't use it while we did our trip
http://10mileseachway.blogspot.co.uk/ so it was dead weight but she is a bit older than yours but no issues with panniers (see pics on blog) and will last for years.
Our trailgator had various replacement parts and often needed tightening and re alignment.
Either system I definitely recommend them using their own bike just because its theirs
Howard