I shop it annually. I have an independent broker who shops multiple companies. I use GEICO as a benchmark and I also shop it with Costco/Ameriprise.
This last time GEICO came in about $80 less... not enough to switch mid-stream but I will explore it again at year-end when my policies are up for renewal.
So my advice is to pick and independent broker, then a couple of other potential benchmarks and shop it.