Kickass review of 429C from Bikeradar.com
Here's a longer version in PDF form, and they pick the 429c over a few other competing models.
I can't wait to ride one of these.
Here's a PDF of the entire "shoot out" from the magazine, which includes their reviews of the Turner Sultan, a Divinci Atlas, a Stumpy Sworks carbon and the Mach 429c.
It's a good review, they seem to like all four of the bikes. However the Pivot does take the prize in their "final verdict" section. The most interesting thing I found in the article was they have the weight listed as 28.8 lbs, without pedals, for the complete bike with the XT build kit. That's the first I've seen of any mention of the bikes actual weight.