From the brief reviews I have read by journalists that have driven prototypes it sounds like the X6 will be a very impressive machine once you get behind the wheel.

It is going to be very interesting to see how the X6 does and whether there are sufficient people that want the dynamics over the practicality. I honestly think the rear seats are a major issue...people do look at practicality. I have lost count of how many people have rightly criticised the 6 series for it's poor packaging having very restricted rear space for it's size. It's cost BMW a lot of sales in my mind. I think only being able to carry four people will be a similar problem for the X6.