Tad's comment notwithstanding, I have owned 4 H-17 sails since 1991. The only one that started to delaminate was the one I bought in 1992 - and it didn't start until 2002!

I consider 10 years of use out of a sail quite acceptable. The sail was still usable, BTW. Just not for racing.

I suggest you talk to the guys in HCA Division 11, which has the most active group of 17 racers in the country. They can give you the real scoop.