The look of this rig is truly amazing!
How's the comfort of the driving cab? Any driving fatigue, or does this thing feel like the rolls-royce of overlanding? This is the first thought that comes to mind when looking at these older chassis.
I don't find it uncomfortable, but it is required to be driven. The air suspension is a critical part in "comfort", in my opinion. The upright seating position doesn't allow for stretching out, compared to a 5500 chassis, for example, so while the ergonomics aren't uncomfortable, it's not a "swallow me into rich alcantara and massage me" kind of feel.
It's louder, but not difficult to have a conversation. If you wanted to wear headsets, you could, but that would only be a cool factor.
My only personal comparison is between a Kodiak chassis and a 4500/5500 Dodge, or F550 chassis, and I find that difference to be very similar on the Brazos chassis.
As it's owner has not been off road, I can only expect the seating position would allow for a better view while navigating, and the cab over design offers nearly an unobstructed view out of the cab, again, using the comparison of a 5500 chassis. I do find myself sitting more upright in the truck chassis when offroading, with or without a spotter - I don't know if it's a habit, but I'm trying to look over the hood, even though I know good and well I can't see through it. Here, there's no reason to.
My opinion (which you know what they say about opinions) is that it's a mix of both. It's a bit to absorb on the outside, more utilitarian of a sort, but inside the living quarters it turns into an entirely different rig with solid surface countertops, teak accents, and a quiet place to rest.