We also have both. They are both older campers so we don't have a lot of money invested. Our 5th wheel is a 2006 Cougar 29RL and the truck camper is a 2001 Lance 1030.
We bought the truck camper for a West trip we took last year. Now we plan on keeping it for those kind of trips. The Cougar we use locally for long weekend trips as the extra room and tank capacity is nice to have.
The biggest hassle is since my 5th wheel rails are on the bed floor when I want to use the Lance I put down platforms to raise it above the rails. Which puts it 2 inches higher than it should be. Not a big deal but still something I have to do.