How good is the M-Class for towing?

This summer I had to tow my 3 FJ40 Toyota Landcruisers from Los Angeles to the High Sierras near Lake Tahoe. I flat towed with a plain tow bar - The Toyota FJ 40 weighs in at around 4100 lbs. The distance was 442 miles, consisting mainly of flat freeways but included one steep pass on I-5 and very steep grades on HWY 49 and HWY 193. I used my ML320 as well as my Jeep Grand Cherokee 4.0. There was no noticeable difference between both vehicles when it came to handling the heavy load. Both of them felt very stable and safe. Braking was effortless with both ML and JGC with no noticeable brake fading - that's pretty good, considering that the brakes had to handle almost 8500 lbs. At speeds around 55 mph the trips took around 10 hours including breaks and gassing up. I noticed one significant difference between the two vehicles: The trip with the ML320 was much less tiring than with the JGC. Since less driver fatigue is an important safety aspect, my ML got a first "thumbs up" in this category. Also: When it came to driving the steep grades in the Sierras I used the ML's unique ability to employ low range on pavement ( a feature not available in current and 1999 Jeep GC ). Low range gave me 2.64 times the regular torque (with a top speed of about 50 mph) and towing my 4100 lbs Toyota up the hills was a breeze. Never was it so easy to tow heavy loads. More "thumbs up"! I used this feature also around town and noticed a good drop in coolant temperature -- this will help to increase the life of your automatic. More about towing and low range Also: lower temps in low range Mpg comparison ML320 vs Jeep Grand Cherokee 4.0 .