As a new MDX owner and having no pre-conceived notion of the noise problem, I must say the MDX is as smooth as silk.. like a fine sedan. We have had such a stormy and floody weather in this area yesterday and today (even on national news), it was definitely a great way to test the road handling of MDX and the comfort level of its drive. The MDX passes my test.. on a very WET road, the handling, even acceleration went just so nicely. Whatever that automatic feature to send the power to the back wheels.. it works. If I push the gas paddle hard, I can feel the wheels "grab" the road. On my regular 325i, I can feel the car "float" on the water a bit as the wheels overly accelerate.
So.. there may be anything better, quieter and what not, but I am just happy with the 'X.