Public vs. Private land is a big difference between East Coast and West Coast wheelin', and it touches a bit on your point Mike.
Out here these days, with few exceptions just about all wheelin' is confined to private off road parks. In my area they tend to be in the + or - 1000 acre size, so you can get by without haulin' ass to traverse the park. But, places like Tellico (god rest her soul) and Windrock are large by East Coast Standards (think 50-150,000 acres), and if you can't haul ass comfortably you are definitely into lengthy trips between obstacles. Places like Moab, Colorado and (I assume) JV - long treks are par for the course. For me, those long treks on the trail are what I enjoy most - but your rig does need to be able to suck them up to make it enjoyable.
That said, I think any decently built rig should be able to handle moderate speed on bumpy roads without requiring a subsequent trip the dentist...
We measure in acres. Out west they measure in Square miles. 640 acres is a square mile.
All the people I wheel with don't wheel if it is sloppy. The hills drain pretty good, but usually the access roads end up with mud holes.