When we bought this house I went through the trouble of calling all the other companies again - I usually do once a year since every 6 months is more of a hassle than it should be. There isn't a company out there that could match my Progressive policy since it has all kinds of discounts for being with them so long. They also offered the biggest bundle discount for the cars and house.
I even have two separate state policies (one for 2 cars in Texas, and one for 1 car in Florida) and I'm still at $1000 a year. I can't complain.
But yes, I agree on calling at least once a year before you need to renew.