The VTM-4 works well. It kicks in when it senses a wheel slipping and disengages when it's not needed.
That picture of me coming down the trail was repeated a few times. I had to back up that hill a four times until I was happy with the picture.
The first time the wheels slipped for just a split second, then I went up the hill, in reverse! There seemed to be no difference in the way it handled and I couldn't even tell I was in 4 wheel drive, but I knew I had to because in any other car the wheels would be spinning. The only thing I don't like with the VTM-4 is that there is no 4-wheel low, but I'm not going to be doing any rock climbing in it anyway.
This morning I got the chance to test out how well "Sandy" does on ice and snow. Only got about 2" last night; but it was wet and turned to ice as soon as someone drove on it. Then it got covered by more snow. I'm impressed. Subdivision roads were glare ice when I left for work. Really tried (within reason) to get the wheels to slip and couldn't. VTM seemed to work very well and seamlessy. Had to stop on a hill for a traffic signal and just drove right up after the light turned green. Don't know how it will work "off-road" but for the types of weather related driving that I bought it for my feelings are YEEEEEAAAAAHHHH.:2:
After my brief offroad excursion in the Pilot... i have to say that the VTM 4 works pretty nicely. Its like having locking differentials. But the disadvantage for the PIlot are 1) the passenger car tires 2) ground clearance 3) no low range
as soon as the Azusa offroad park opens back up... i am gonna test it out a bit more... entrance to the park is across a rocky river bed that can either be dry or with water depending on the weather. Because of the ground clearance i just have to navigate around the rocks.