Hello everyone! This is my first post but I have experienced riding a new '07 X2 Deluxe with the ADC feature and want to let you know my thoughts on it. It as said here does provide 4 wheel engine braking unlike the standard Polaris rear wheel engine braking that most are familiar with. It really comes in handy on steep rocky or muddy descents. In AWD high range the rear tire skidding or "ratcheting" is a thing of the past. The rear tires may still slightly skid in AWD low range or reverse due to the high gear reduction in both ranges. But in any mode, the vehicle does not ratchet the rear tires and is much more controlled than non ADC equipped vehicles. My buddy owns a '06 800 Sportsman and tried this new X2 out with the ADC. He went down a pretty gnarly hill and said he will be trading in his for a new one with the ADC. He told me that he didn't have to use the brakes at all and actually had to use throttle to gain momentum as he was almost stopped on the trail. Likewise, he said he gets cramps in his hands from constantly using the throttle and brakes with his machine to navigate similar hills to keep the rear wheels from sliding him sideways. I have also found that this mode is very handy to have when climbing down rocky or log strewn hills with a loaded trailer! I would go as far as saying that it handles better than other ATV's with four wheel engine braking that I have ridden because the steering effort is much less than the others. This allows you to navigate the terrain around trees and such easier than the others.