This is the first write-up I think comparing a GMC to a BMW . Congrats on the purchase though . As far as cabin noise the X5 I believe has one of the best decibel ratings at high speeds and you can hit 85 MPH but sounds like you are going actually going 35. So, you might want to check your alignment or get your tires rotated, etc. A far as cargo space, the Envoy is longer so it's going to carry more. Enjoy.