I'd take a good look at Foremost. If you're a part-timer, or use a seasonal site like us, Foremost allows you to temporarily drop the collision part of the coverage while the rig is parked or stored. Saves a few bucks. Liability, theft, fire, everything else remains in effect. They're also very good about claims, too.
I know for certain that State Farm's coverage does not allow you to do this. And the Foremost policy also covers roadside assistance on your TV, whether the rig is on it or not. Foremost also has total replacement coverage, not depreciation, if something unthinkable happens to your rig.
www.foremost.com