We bought our F250 diesel to haul our boat.
We sold our boat and bought a Jayco 22FB (27').
We sold the Jayco and bought our current tt (32').
We bought our current tt because we plan on fulltiming for at least two years.
The tow vehicle has stayed the same though each thing we hauled with it got bigger and heavier.
In a few years, we plan to go back to a boat which we will haul with our F250. We never really got the itch to go bigger but our needs changed. The Jayco was large enough to live in but we thought it might be easier with more storage.
If we had a couple of kids at home, we would probably opt for the extra space. Of course, we could have hauled our boat and our first tt with an F150 but wanted to buy 'our last truck first.'