To the one who PMd me.  I accidently deleted your message trying to make room to send you a reply, so I don't know who you were.

To answer your question.  There is no doubt in my mind that these belts are good for 100,000 miles.  However, I have not taken one there, well, almost, sort of.  Age will get your belt before wear will.  I mean that if 24,000 miles is recommended mileage, that's about a 4 year old belt if you are an average rider.  For me, that's 1 year, and I ain't changing my belt every year.

I've ran one for 45,000 miles, then used it later for a spare and put about another 30,000 miles on it before it, and my pulley, got trashed when the belt guard came off.  The safe thing for me to tell you is, go by the manufacturer's suggested maintenance.  My personal advise is to inspect it often, for nicks and wear or rot.  Keep it properly adjusted.  I find this is set and forget, you never have to adjust it, even when you change the tires.  But do check it to be sure.