My wife and I picked up a pair of these at the start of the summer, and I've put close to 200 miles on mine. Living in Park City, my riding is about 70/30 cross country/ moderate downhill. This bike has handled absolutely everything that I've thrown at it (or thrown it at...). It climbs like a champ, and the lock outs on the shock and front fork keep the frame very solid for the way up. The shock and fork are easy to adjust (make sure you have a shock pump to adjust the air pressure), and have good travel and rebound for moderate downhill. I've found the frame to be pretty stiff - being a single pivot rear suspension, it will never be as stiff as a VPP, but I haven't had any issues with ghost shifting or wobbly frame at speed. The only time I really notice flex in the rear is in tight cornering at speed (mostly switchbacks). Even then, the flex is very predictable once you've been through a few turns - it feels more like the rear wheel has a little float through the turn rather than being super loose and noodley.
While you could certainly upgrade the components, I've been happy with the stock components on the DXC kit. The shifters are quick and snappy, and have only needed one quick adjustment for cable stretch after the first hundred miles.
Gripes: The one upgrade I'm seriously considering is the brake set. The stock (Avid Elixir 1) brake set gets the job done, but isn't the greatest for longer downhill rides. I've never had an issue stopping, but I've definitely gotten the pads and rotors pretty toasty on longer descents. Also, the stock tires are decent for dry hard tread, but they gum up pretty quickly in mud. I would invest in something nobbier if you're riding wetter trails
Bottom line: This is an awesome bike if you're looking for an intermediate FS XC bike, and a great bang for your buck in the posh world of FS 29rs.