Dear LeMansX5,
I would not say that. We just see him sitting but I'm sure his head is touching the roof. I've seated exactly at the same place during the Geneva Motor Show 2008, you feel a little bit opressed when installed at the back seat.
I love the X6 concept, look and performance, but it's a pity to have such a big car and have so small space inside. A panoramic sunroof would for sure bring a better feeling but is not available on X6, just a standard sunroof above front seats is available.
Also the trunk is not very accessible and because of the Coupé shape, you will not be able to load many things in it. I think it is just perfect for a golf bag ;-)
So X6 is very far of the X5 concerning the inside space and utility capabilities.
Anyway, even with these defaults and the fact it will not suite my needs, I would love to have one.