Are those your only two options, i.e. are you buying off the lot?

With one kid, depending on if you have other needs, I would loose the third row seat. It's been a while, but as I recall the amount of stuff you have to carry is inversely proportional to the kid's age, and the big open back area is better in my opinion, plus the utility of the seat as seats is questionable. With a lot more, older kids maybe.

I have the 4.8, and test drove the 3.0. The 3.0 was just fine until as you did, I drove the 4.8. My wife still says the 3.0 was just fine (says it and says it and says it). I'm glad I got the 3.0.

I'd also agree, get the sport. Or at least get the upgraded seats that come with the sport, I had a friend who had both, and that was his one immediate recommendation amongst all others when I said I was looking at the X5.

If I had to choose -- well, my wife would choose the 3.0 instantly, and if I could not do both I think I might as well. It's got enough power. And your gas mileage will be better. Probably insurance. And you do have the college fund to start putting money into.

But if you are ordering, maybe just swap around, loose the running boards, HUD, 3rd row -- maybe you can pay for enough to get the 4.8 and sport both.