We have a 2019 23H "Freedom Elite" which is Camping World's version of the Thor 23U, which we purchased new in 4/2019.
We have many miles on gravel roads and very well maintained dirt roads with no issues. I do not think this unit would do well at all on soft dirt/sand roads, mud, or even slightly off-camber. I see an issue with overhang and clearance, even though this is a relatively short rig with a proportional wheelbase it is still relatively low compared to a (CC/LB) pickup. Tail dragging being the biggest weakness IMO. I don't see how brand could affect its handling or capability assuming length and wheelbase being equal (minus an optional locking differential or something, which as far as I'm aware no class C manufacturer offers.) My Ford chassis has F and R sway bars standard.
This is my third RV and by far the tightest so dust hasn't been a major issue for me so far. But pnichols' thoughts on dust mitigation are definitely worth considering and we will for sure be trying that in the future.