A real 4WD system (like on 4X4 pickup trucks and Jeeps) with a lockable rear axle will be just as good as the Subarus. I suspect that the rear differential gets locked only when you use 4X4 L mode though... not sure that the rear axle gets locked when shifting from 2WD to 4X4 mode at freeway speeds.
Locking the rear axle on a truck or a jeep is a terrible idea on a snowy and icy road. It will send you all over the place and walk your vehicle sideways down any slope. A rear diff can (unless modded) usually can only be locked in 4l and under 5 mph. A rear locker is select able (unless of course if you have an auto locker which is after market) and will never lock on it's own. A 4wd truck is as good as an awd car like a subaru if the subaru has a locking center differential, giving dedicated power to the front and back wheels constantly.
A part time 4wd truck (with a transfer case) in open diff mode will always have one wheel with power on each axle, an awd car with a locked center diff will be the same, one wheel will always have power in the front and back. As seen in the video awd cars with a computer controlled traction system without a locked center diff will only send power to where it thinks it is needed, not necessarily sending it to one wheel on each axle.
The biggest problem with 4x4 trucks is not the 4wd system or the tires but lack of weight on the rear axle. An empty bed is so light that the rear end can break loose super easily. If you have a pickup you need something in the bed to weigh it down. I used to load my Nissan 4x4 with about half a dozen bags of tube sand just to make it driveable on packed snow and ice.
In 4wd my front pulls the truck forward pretty dam well and the back end hardly ever breaks loose. Yes weight over the axle would help, but i find it unnecessary at least for me, just because the front keeps the truck going straight very well.