[acalian]

Completing the test on both cars - want to share my impression with the community.
As driving a lot long distances, day and night in any weather conditions (especially in winter) - I've paid attention to the abilities to make driver's life easier being 5-6 hours behind the wheel.
1) Overall comfort level in ML 350 much better then in Tuareg. MB much more quieter inside and outside.
Inside insulation is terrific - no sound from engine, tires (on purely paved roads) and even wind when you on highway. Seats and suspension more driver friendly (softer) in MB (even I drove a sport timed option).
2) Night driving more attractive on MB - excellent road illumination from head lights and auto-dimmed exterior mirrors make your night driving much easier.
3) Safety features on MB such as blind spot indicators, line change notification, and drowsiness alarm very useful and not available in Tuareg even on high level.
Many other parameters (handling, acceleration, braking, etc.) on both pretty much the same.
Tuareg has some advantages to MB - huge panoramic sun roof, compact spare wheel, but they are not important for me.
Haven't tested drive-terrain and assume they are better in Tuareg, but I rare drive off-road and think the chance to be in the ditch driving MB is less (having all the features in it preventing that).
Customers rated Tuareg TDI 95% compare to 84% on ML 350, don't know why. Need to do more research to figure it out.