Big thread about this in the Military section.
I switched to State Farm 2 years ago for the same reason. After dumping USAA received my Subscribers Savings Account check six months later and that paid for my insurance that year, home and 3 cars.
I tried to see USAA they would do something about the rates to keep me and they said no. When I called to cancel then someone tried to see what they could do but I told them it was too late.
I like having a local agent, he even calls me to wish me a happy birthday!