From what I have played, I cannot overstate just how much more character there is to offroading, and it gives the off-road vehicles and SUV's a place where they can finally excel. (And this isn't somebody who runs an off-road club saying this, this is just a normal player)
The SUV's and trucks within Horizon 3 just felt like vehicles that were heftier, and considering the physics, just made it so that both supercars and SUV's/trucks had the same sort of net losses from going off the tarmac. Here, it feels like the offroad vehicles, SUV's and trucks very much are more capable off the road then your standard F-Type or whatever. I had a ball playing around in the snow with the Class 5 Baja Bug.
What also works in the off-roading's flavor is just the verticality of the map. Much has been made about how flat and at best undulating Australia in H3 was. Here, you're scaling mountains, the hills are much more harsh in terms of their peaks and valleys, and the variety in seasons adds to it.
Finally, you can see why PG has added not just the usual gamut of performance SUV's and trucks, but also pure off-road vehicles, and it doesn't feel like a waste. They truly feel like they are apart of a roster and not just an island in a sea of sports and super cars.