we've had farmers for about 20 years (used to be AIG).
every few years, i get quotes from a few different insurers, and not once has any other company been able to come close to what we are paying (allstate, geico, liberty mutual, esurance, etc).
geico was especially annoying: i told them that we weren't interested because they were over $400 more, and they started calling almost every other day asking if we were ready to switch to their company. it took the threat of a harrassment suit to finally get them to leave us alone.
unfortunately, there are so many variables with insurance (location, driving record, age of cars, etc) that you really need to make a few calls to find your best rate/coverage.
ggod luck