I don't really know what your plans are for the Thorn you're considering.
I'm completely new to touring (though not new to cycling), but decided a few months ago that I would ultimately like to ride the Great Divide and bought a mountain bike recommended to me (I knew nothing about mountain bikes then). It turns out I cannot load this bike in any way, or take a trailer. Since retiring, I have done plenty of trail riding on this bike, loving it, but realise I also want to tour both on road and trails. So I have decided to get myself a decent tourer that will do on or off road. I will be doing plenty of European tours where transport is not an issue, but I also plan to visit the USA for lots of tours in the future, starting, I hope, next year with an educational tour. The question for me is Couplers or no couplers? At a £400 price tag plus £299 for the recommended case (although I'm sure I could purchase one for less elsewhere), I have to know that the couplers are suitable and will be worthwhile. The more opinions and information I can get, the easier my decision will be.