Phillyguy - we do have large tarmacs of snow and ice here near Buffalo - they are our roads in the winter. We had an Odyssey before the RL along with our Pilot. I've also had a bunch of FWD cars before as well as AWD and "true" 4WD pickups. You propos that the AWD system in the Pilot/RL is fully disengaged at higher speeds. That is flat out wrong. A lesser percentage of power is certainly being applied to the rear wheels, but once the fronts begin to lose traction, the system absolutely sends more power/torque to the rear again. The system is among the best I've experienced, including comparisons tonthe AWD setting in my previous GMC Sierra and our old Forester.
I am not proposing that the VTM4 system shuts off at higher speeds, just pointing out that I think it would be difficult to tell that it is operating at higher speeds since a FWD car or an AWD car will feel the same going in a straight line down the highway.
What I am proposing is that minimally at higher speeds (if not all speeds) the VTM4 system will cut all or nearly all torque to the rear wheels as soon as the slightest bit of steering input is detected in order to prevent any drive line binding.
I am also not very clear on what a system like VTM4 is really going to do to assist the driver on the highway moving along at highway speeds. It may reduce some torque applied to the front wheels during passing, which would free up some traction for steering purposes, if the system doesn't shut off when steering input is detected. Likewise when entering a turn, losing traction, and regaining traction it may help in righting the truck, if the system doesn't shut off when steering input is detected.
I have played around in multiple Hyundai/Kia vehicles which use the BorgWarner iTM3e system, and my very unscientific tests with locking/unlocking the AWD and turning upwards onto a hill in wet conditions always results in wheel spin, which I interpret to mean the car's computer is extremely conservative and shuts down AWD when steering input is detected. The iTM3e system is fairly similar to VTM4, BorgWarner makes both systems, the iTM3e doesn't have the funky rear diff though. The programming controlling them could certainly be very very different though.