We have had National General for nearly 2 years without issue. But really, until you need them, you won't know if you're going to have issues with them.
There's always a bunch of talk about making sure you have an insurance company that focuses on RV's. While some of it may be hype, I can see the value in that, especially for a nominal difference in price (which appears to be your situation). For nearly everything else in our lives, we make selections for services based on the provider's familiarity. Everything from our haircut to our mortgage lender to our doctors. So why not pick a company that primarily insures RV's instead of one that primarily insures automobiles.
If I were buying anything brand new, I'd pick full replacement value initially and then consider adjusting down the road. Its always good to shop insurance every few years anyway.
