I have always spun students at an appropriate point in their training, as a demonstration excercise only.
Whilst most modern aircraft are benign under normal circumstances, I feel that there is real educational value in teaching that if you abuse an aircraft it WILL bite, and steps should be taken to avoid the situation arising in the first place.
My favoured tool for the job (like WWW) is the pa38 which despite its unjustified reputation, demonstrates inadvertant spin entry perfectly, and predictably.