"XC racing is like sleeping on the floor: it's hard, but if it's all you know, you get used to it. Endurance racing (50-100 mile+) is like sleeping on a bed. Once you've slept on a bed, it's way harder to go back to sleeping on the floor."
That's funny...I'm just doing it for training and mix in the higher intensity workouts. Same thing I did with Tri's mixing in the shorter stuff. Dropping 5:30 miles off the bike is still way easier than this XC stuff...but then again running was my thing prior to my hamstring injury.