Wheeler - The most time I've spent in the new seats at any one time would be about 4.5 hours. That was for about 2 hours on the road and 2.5 hours on the trails. They rode well and I had no issues. Due to the seat bolsters and side bolsters, you are held in place that is for sure. They felt great off road with all the jerks & shakes, and not bad for every day driving either. The OEM seats just didn't feel right to me. They felt like I was riding "on-top" of the seat in not "in" the seat. Sort of like driving on a milk crate with a stiff cushion (yea, been there, done that....drove like that for 60 miles, not comfortable nor very smart thing to do.) I'm happy with the ProCar Rally seats in my rig.
I will say this, if you wear a size 36" (maybe 38") waist or plus in pants/shorts, these are not the seat for you. The seat bolsters are deeper than most, and would not be comfortable for peoples with....uh......humm.....well, you know.
Being that I just can't leave well-enough alone, I've been looking at the ProCar elite lumbar 1200's. They seem to have a wider seat and the bolsters aren't so pronounced.