My mom is currently negotiating on a new Q7 3.6. They are very thirsty vehicles. She's coming from a Cayenne but still expects to pay more for gas with the Q7, however, the diesel variety should be a better option. It certainly is large, in fact, it won't fit into our garage as it is currently construted so we will have to have some shelving moved, as a point of reference, the Cayenne fit in with no problem.
I like the Q7, it's not sporty at all, but I think it is a classy, stylish suv. I would not consider the X5, I don't think you get what you pay for with it, and I find the interior to be very blah - my boss has one and is not overly thrilled with it (electronics suck).