Been to WDW twice and French Pyrenees with a recce into Spain without any problems either for me or the bike (now touching wood with several parts of the anatomy!).
The 996 is absolutely fine, so long as you are moving around in the saddle and enjoying your riding - so that means 130+ on the autostradas then
I'm over 6' 2" and the wrong side of the half century and the only time I've suffered was a long trip up the M40 in February - had to be lifted off the bike at the end of that one!
[Edited on 26-11-2004 by captaincardigan]