I'd say 06 ML is much better than the old model.
I have 06 ML 350 and can say that the suspension is a lot softer than E53 with sport pkg, not to mention my X
But, as a family car I actually like the softer suspension as on long drives you don't get annoyed of the bumps coming through, especially here in Bay area.
I drove the ML couple of times in Europe and I think that the suspension setup is stiffer there.
Steering of the ML is not as accurate as X5's, not even close.
ML 350 engine pulls pretty well for that size.
Haven't driven the E70 yet and I try to stay away from the dealers for a while