X5 storage space with third row seats

[Spanky Deluxe]

Hey all,

We're thinking of selling our X3 and getting an X5 instead. Can anyone comment on the luggage space with the seven seater option? Particularly with the third row seats folded down. We'll very rarely need the third row but it could come in really handy for ski trips with friends (last year seven of us went in two cars) to save on travel costs (with a big roof box though). I'm just wondering how general boot space is without the boot seats in use and how it might compare to an X3.