One of the big issues with most older people is mobility.
The cab design of a Fuso/Isuzu has the steps near the door hinge, so this can make it a bit challenging getting in and out of the cab.
The higher the cab, from the addition of singles or parabolic springs, compounds this problem.
Personally, I am not a big fan of the new 3.0 litre "world engine" that is now being used in the Fuso, but that does not mean it is not a reliable motor. I just don't see it as a "truck" motor, like all of its predecessors have been.
The vehicle you have linked to I would consider as a good "rough road" camper, but it is probably not suitable for heavily rutted, off road tracks, given the ground clearance. This is not one of the crappy FGB71's that came with no low range, so that is a good thing.
I am wondering if this is an ATW build, as that pass-thru sock looks like one of theirs. If that's the case, it probably also has a kinematic mount system for the subframe, which would be a good thing.
All things considered, it looks like a pretty nice camper.