I've been with USAA for well over 20 yrs now and would not think of switching. The had no problems with my Smart or any of my other vehicles and after 2 claims in all that time my rates never did make any drastic jumps.
They also financed my vehicles, do my banking, cover my home insurance, and handle all my investment capital. When I first joined way back when, they used to be only for military officers. They have since relaxed their eligibility requirements. Now, all my kids have switched to USAA also. I think you still need to have some form of connection to the military, but you no longer have the strict requirement for being a military officer.