Comment/question..
Isn't one of the inherent problems with IS, the fact that they tend to "jack" when the body is rolling? With high CGs, the body rolls so far then it will suddenly "jack" to the outside. This would explain a couple of things...Walkers comments on how their's worked 9 out of 10 times, (but the tenth being so bad!). Also why the M151s had a nasty habit of suddenly flipping over. Even Hummers suffer this sudden jacking effect, although it takes more to get em to that point, than the M151s. I even remember Volkswagen bugs being bad about this!
I believe this is due to strange roll centers and/or the way the roll center moves during suspension travel. The Hum-Vee is helped by its great width and the fact that its height isn't achieved through severe suspension angles but rather the offset drives at the wheel. This kept the suspension geometry reasonably level, such as a stock, civilian IS vehicle