I purchased this machine new 2/5/11. Put just over 100 miles on it. This machine is incredible. If I had to describe this machine in one word it would be "smooth". I am not a professional rider. I was looking to get off the 2-stroke treadmill and I bought my first 4-stroke sled; the 2011 Yamaha Apex SE. Previous machines I've owned were a 1993 Yamaha Venture VT, 1995 Arctic Cat Panther Deluxe and a 2003 Yamaha SX Viper. Although the Apex tips the scales at over 650 pounds, it rides and handles like my Viper. Also like my Viper, the Apex has the interesting and unsettling trait of trying to rotate the sled (and the driver) clockwise upon hard acceleration due to torque. Yamaha offset the skis on the Apex 15mm to help offset the torsional bending of the frame. The Apex front suspension is equipped with Fox Float 2 air shocks. The rear suspension is equipped with a Fox "Mega-Float" air mono shock. This thing is enormous. Fox and Yamaha claim this shock cannot be bottomed out. The air shocks can be inflated to a maximum of 225 psi for the most extreme and aggressive trail riding. The sled comes with a hand air pump to adjust the shocks to your preferred riding style and terrain conditions. The newly redesigned 998cc 150 hp+ Genesis 4 cylinder 4-stroke engine has Yamaha's EXUP variable exhaust manifold and EPS (Electronic Power Steering). Combined with the Fox Air suspension, the rider gets very little feedback from the trail. The sled felt very well planted on the trail without the darting I read from other riders. I did have dual carbides installed on the skis and had the track studded to harness all this horsepower and torque on the trails. I can't say enough good things about this machine. The faster I go, the smoother the machine feels. As I said, the Apex performs and handles like my old SX Viper with a more plush and comfortable ride. Fit and finish is impeccable. The deep and throaty snarl of the engine, even at idle, will turn alot of heads. I feel the machine has more engine noise resonating from under the hood than the other 4 strokes I've test ridden and there is some track howl from the tunnel reminiscent of my '93 Venture. The sled is new and the engine isn't broken in until the sled reaches 800 miles. We'll see if things start quieting down as the sled breaks in. Overall, this is the best snowmobile I've owned & ridden. This is also the most expensive stock sled in the industry. However, if you're looking to buy a definitive machine that will last you for many years with high quality, reliability, performance and comfort, then take a good hard look at Yamaha's most technologically advanced flagship snowmobile. The Yamaha Apex.