Congrats, ic you're on the same boat as I was a few years ago, when I got my 2005 4.4. The x fit the bill for when we just had the twins, not for when the third one came along...I was not able to squeeze three car seats in the second row, so I was looking for something wider. The GL was able to swallow all three car seats in the second row, plus i get the convinience of a third row seat for when they are older.

I've had the GL 450 for a few months now, and I must say it is a solid truck, hanldes just fine, and feels tight, the closest thing to a BMW. The third row seats are automatic and they fold flat, this is what sold my wife on the GL...no need to be taking the seats out. Adults that are 6' ft tall fit in the 3rd row seat just fine, plenty of room. The truck is fast too, faster than my 05 4.4.

Anyhow, I am a BMW die hard, however, until BMW comes out with a competitor to the GL, MB it is... SUV wise that is.