Engine off coasting will damage the trans as there are some spinning parts in there w/o lube even though it's in N. It needs to have the oil pump pumping and for that the input shaft has to turn.
Of course the manual boxes are designed to get splash lube no matter what.
As a flatlander, the opportunities for coasting with engine off aren't there and P&G sux. I can see wanting to do extended coasting engine off in the hills like in California. I did do an engine off coast down a mountain in the Sable then I remembered D'Oh! DON'T DO THAT AGAIN!
