Might I add thought that racing is just one thing I do. I would not have been able to justify the purchase of a 'cross race bike if I didn't use it for other things. I would say that riding a cross bike on mountain bike trails is harder but also a little mor eintense. Otherwise tame trails can become interesting. Also, I ride to trailheads. Much more fun doing that on a cross bike than a mountain bike. And of course it makes a quite adequate road bike with the right tires. In non racing applications a cross bike is prety much the thinking man's hybrid.
It should also be noted that some cross bikes are set up more as racers (Ridley, Kona Jake the Snake and Major Jake, etcetera) and some are set up less as racers (Cross-check, Kona Jake, and the Bianchi Axis is somehwere in between)--just like not all road or mountain bikes are made to be raced.
But yes, race a mountain bike in any but the most poorly designed (technical singletrack-y) courses and then do it on a cross bike. You'll understand.
Last edited by M_S; 12-05-07 at 06:55 PM.