We have the unique scenario of having both combinations that you're askkng about. I already had my 5-er toy hauler when I inherited the DP. See my signature for details of both rigs.
The only place we still use the 5-er is camping in the sand (Pismo Beach / Glamis). We prefer the DP everywhere else. We have a Jeep, quads, sand buggy, etc..., and load up the cargo trailer behind the DP based on our destination. The issue for us is that the family is much more comfortable going down the highway in the DP than the 1-ton pickup.
We used to have a gas class-A that we could air down and take on the beach as well, but the truck tires on the DP don't air down the same way. We still take the 5-er on the beach and into the deep sand, without any issues.
If we had to choose, we'd stick with a motor home. We've actually considered selling both and moving to a Super-C that has plenty of towing capacity and can still be aired down to drive on the sand.