The xc racer gals might leave the saddles up, but I won't. I've seen way too many endos ,of people who just won't put the saddle down. I'm sure the racers train to ride like that,who wants the extra ounces of a gravity dropper?

For me, the saddle is just in the way on continuous descents. If I'm in rolling/mixed terrain I will keep it close to climbing height, but for any kind of long descent, down it goes. Our local riding is conducive to this: a big climb followed by a long descent, or long shuttled rides, of XC but down flowing terrain. This is also how I've been coached, and trained to coach. "Canadian style" focuses on a neutral position with the legs some what extended, much more of a standing type position that is taught in the states. You move your weight back and forth through the hips but never get way back. DH racing is a separate discussion. :-)

Gene is very well regarded, but there is no only one correct way to ride.