Being a past owner of a 08 Loaded 4.8i X5 and a new 10 GL350, all I can say is so far, the MB is a ahead of the game. Keep in mind, depends on the driving "feel" your looking for. BMW is no doubt more sporty and stiffer suspension. The GL 3rd row is my main driving factor - seats I can actually use as opposed to the X5. As well, the 2nd row is a little more spacious and the rear dvd + harmon kardon sound system, blow my X5 away. Germans are germans, but the MB is I'd say a little more classy and the X5 is a little more sporty.

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SOLD - 08 X5 (Titanium Silver w/Black Nevada with all options).