Got a Chariot which works fine on my full-sus with discs since it fits to the QR (IIRC the Croozer uses the same or a very similar mount). Attaches very easily without having to touch the wheel QR, since there is a bracket which stays on the bike with a ball joint. The only issue being I had to file the mount down a little to fit in my cowled dropouts.
Would definitely recommend a Chariot – though a Croozer is also a good choice for rather less money (I like the idea of the suspension on the Chariot, though never quite sure how useful it actually is).