I too did one of the demo rides when the Pivot folks came to our local LBS. An awesome bike, though fairly pricy. I currently ride a Fisher SuperCaliber, but if I were looking to buy another FS bike the 429 would be way, way high on my shopping list.

Test ride one if you have the opportunity. The ride is sweet, and handles nicely. If you've got that kind of jack to put into your bike, you won't be disappointed and you'll definitely have a bike that would handle whatever you wanted to do...