Mark Lenox wrote:

I'll teach them spin awareness in something else.

*If* you have something else at your hands.

Fact is, many European clubs have the ASK 21 as primary trainer and
nothing else. Besides, I think it's a good idea to practice spins in a
glider which the student already knows. You can combine this with an
impressive demonstration how glider characteristics change with CofG.
And last but not least, the ASK 21 spins wonderfully with that tail
ballast. I don't see any disadvantages.

Stefan