We have a 25 gallon 4-wheel Barker that is 8 years old and still in good shape. We only use it a few times a year, but some friends used to be camper hosts for about five years at a State Park that had electric hookups only. They had an identical tank and used it at least once a week, pulling it with their tow vehicle, and it held up just fine on paved roads with the occasional speed bump.
The only other tips I can offer is that you will want to use a bungee cord to secure the tow bar to your hitch or it can pop off when you slow down. For filling, I made a special short sewer hose with a Thetford connector at one end and a Valterra connector at the other. I have towed this tank on gravel roads before, at very slow speeds, and it survived. It was expensive when I bought it, but was money well spent.
Epilogue - The work camper friends filled their water tank with about 200 feet of garden hose connected to a distant public faucet.