If you're looking for offroad capability then you're looking at the wrong cars. The Range Rover Sport has nothing like the offroad ability of it's big brother or the LR3. The Porsche is just an exspensive soccer moms shopping trolley. You're right about the Volvo it is a tank but I must say I'm impressed with it so far, my wife's is the 2.9 twin turbo so although it's heavy it's no slouch. If I were looking for something like the RR I would definitely go for the FX45 I think it totally out classes the rest and if we had them in the UK I'd have one now.
However if you want refinement and offroad ability have a look at the LR3.

Col

Jeep Commander - Ugly box on wheels