The Sumo springs and the rear Koni's have been installed. Huge difference. The AI doesn't rock side to side like it did and is more controlled over rough roads. There is noticeably less dive under braking and rear squat on takeoff. Well worth the money!!! My buddy bought a 31" camper trailer recently. We are driving out to western NC tomorrow morning for his maiden trip. It will be interesting to see how the AI works on the interstate. I don't normally wish for wind but I would like to see if it is better in windy conditions.
As for riding on the bump stops, that is what NASCAR is doing. Their cars have become faster once they were allowed to do this. My son is a mechanical engineer and works for Toyota Racing Development He is in charge of tire and suspension testing for the NASCAR teams so he has been very involved with this change. Prior to working in NASCAR he spent 12 years designing race tires for Michelin. He learned a lot at Michelin but there is much more money to be made in NASCAR!!! Doubled his salary when he made the switch.