Hi Barry and welcome,
I think it depends on what you're used to and what your expectations are.
We have a wizz bang pillow top mattress at home very soft and comfortable. Yet the foam in the vans is only 150mm thick or so, on a solid base board, so yes it feels quite hard comparatively. (But doesn't bother me)
You'll find a number of posts on here with differing opinions of the inner sprung and of the foam, so you're unlikely to get any one definitive answer. Most display models at the resellers will now have inner spring mattresses, so go to one and lie down on them for a while and see what you think.
As Barry mentions above, we also have the egg shell overlay which can be picked up from K-Mart, Clark rubber or other such stores.