I also have State Farm and have been with them since 1968. They are the largest causality carrier in the country, with 6& of the business. They normally have the best rates but a local or regional carrier could give you a better rate.
USAA has the best rates, but you have to have a military connection to qualify. Also, they act as a general agent for another company on RVs, and don't write policies themselves.
Ignore the advertisements on TV over the best rates. Look up the ratings in Consumer's Reports. You can find a copy at your local library.