Ironically I once owned 2006 Trek 8000 - bought it from a semi-sponsored rider who had only raced it twice and was down on his luck.
Swapped a bunch parts, built up a killer set of mavic wheels for it... located a NOS Syncros stem and Ritchey WCS bar... came in at 23.8 lbs with the continental kevlar tires.... had it for three years...
But I have never missed it.
It was seriously a beautiful bike. Nothing I could actually complain about it. But it never felt "right" for me if that makes sense.
Sold it (kept my wheels and saddle) to a friend getting into XC racing and bought a 2000 Rocky Mountain Hammer Race and been happy ever since. Go figure eh.