D97 or D10 seems to be much preferred over Fast Flight these days,
D10 didn't stay around long--little difference in it and Dynaflight '97. Force 10 x-bow material is basically the same thing as D-10.
I like Dynaflight '97, have used it for years, but it's loosing ground to materials like 8190 and 452X and Trophy.
I'm curious to know what the next big thing in string materials will be--they have gotten so good I can't see any room for any kind of major improvements.