There isn't a massive different across the RS range however if you take a 182 Cup, add some recaros, lower springs, sach dampers and steering revisions etc... you end up with a better car ofcourse ie. the Trophy.
Steering revisions? Not heard of any changes they did to the steering?
(Fan of the Trophy by the way)
apparently they did! but you will have to be a bloody good track driver to know the difference !