From what i understand Honda and Toyota actually recommend you inflate your tyres on the Prius and Insight to quite high PSI, as there is less of a footprint on the road and you get better fuel economy, but hey, they only have a bit of a car on top.
The best thing about 4WD'sis that they resond really well to changes in PSI. Lower PSI means better grip, higher gives better fuel economy. and they also handle differently, i'd imagine having a lower PSI would create a stickier footprint for the car during cornering.
for what i know, i like 4WD's, not SUV's, such a subtle difference to, say, Karrmann but thats like saying all Hybrids look alike (They kind of do, the whole space age thing they have going on.....)
If it has road tyres, it's a road car, if it has 4WD tyres, it is a 4WD, if it has in-betweens, then it's driven on both surfaces.
Pretty simple.