I custom ordered a seat with more foam, etc. It was not a Bostrom. This helped quite a bit but my time behind the wheel was still very limited.
I finally bit the bullet and went for the major back operation. I'm now held together with 6 bolts and 2 titanium rods. Not the most fun to go through but after about four months I drove the coach 400 miles. That was a few years ago and now I can drive all day. My back is stronger now that it was when I was a teenager and now at 70 there is not much that I can't do. Back pain is a bad memory of the past. Unfortunately I can no longer use the back pain excuse to get out of doing the wife's projects. If you have a mechanical problem with your back, changing the seat is only a temporary solution.