I drove the new one last week - HSE model, not supercharged. Compared to the 2005 Rover (BMW 4.4 motor + 5sp): Feels lower and longer. Steering not nearly as responsive, but vehicle more stable / less body roll in sweeping corners. Weirdly, doesn't feel any lighter, and is much less torquey off the line. Interior and exterior detail is nicer - leather covers everything even in non-autobiography models - front seats are less bench-like than before, but the worst part by far is what's behind the front seats... Headroom is drastically reduced, rear seats don't even fold flat, and space behind the rear seats is much less than before. Bottom line is it drives like a big, heavy car - no longer "trucky" in feel, and it doesn't have much cargo space.
So, seems the folks who commented above are exactly right. I came away feeling the new one was designed specifically to ride to the mall in luxury and style LOL. Pathetic. I would never buy the new one.
Comparisons: the current X5 is much sportier with almost the same interior space (X5 35d FTW). ML63 as sporty as the X5 (non-M), plus rear seats fold flat which gives more cargo space (didn't drive any other ML). GL550 is a similar driving experience but much more room in back than the new Rover. Q7 diesel - similar feel as well but feels cheap compared to all the others.