I have been riding a 2007 GF 26" HiFi Pro for the past five years and finally decided to switch to a 29er. Based upon everything that I read, demo'ing a SC Tall Boy, a Specialized Epic, and the 429, and taking into account my normal riding - all XC, Leadville every year since 2007 - I bought the 429 and could not be happier. 2012 429 full XT build. I have not weighed it nor do I intend to. I'm 5'10" and 190lbs with a 31" inseam. I have a medium which fits perfectly. The stiffness, manueverability, and stability on climbs, are all as advertised. This bike is a blast to ride on singletrack. And on technical parts of trails with rock gardens and loose soil, it blasts through it. My lone concern with the bike is the minimal clearance between the lower part of the D-Link suspension and the rear wheel. there is almost no room for error there. I have yet to ride on a really muddy day but that may not be too fun. This is a perfect bike for Leadville and for flying around my local trails in MD - Schaeffer Farms, Holyes Mill, Black Rock, Watershed. If you are considering a 29er and are more into XC and singletrack, you cannot beat this machine.