The point is that high performance cars offer much more driving satisfaction, while the big SUVs offer little utility to the driver who don't need to haul lots of stuff. Compare performance of X6 to M3 doesn't make much sense.
SUVs serve a lot of people who want higher driving position, feel powerful (seeing over the road), and an image of being powerful. Wagons are the way to go for utility - whether Accord wagon or 5 series wagon, although 535xiT isn't cheap by any means.
I think the DPC technology will go into the 5 series xdrive vehicles soon.
2008 528i: Ti Silver/Black/Light Poplar Wood, ZPP, ZCW, STEP, Comfort Seat, Heated Rear Seat, PDC, Xenon, Nav, iPod. 35% ceramic tint. VentureShield Clear Bra.