I have been with State Farm for 10 years now and have had good luck as well as good rates the entire time. I havent (fingers crossed) had a collision yet, but have had 3 comp claims and all of them were taken care of quickly. Here in MN our glass coverage falls under comprehensive, and has no deductable which is nice for the MN winters where your windshield picks up a crack from either the cold or road debris. I am also a face to face person when i have problem with something with my car, and having an agent who i can go to and complain to when im not being treated right has been very good.
I have shopped around for other insurance just to be sure i am getting the best deal and saving the most money, and after 10 years with state farm i havent been able to find anyone who is willing to come even close to the same rates for the same coverage. in fact USAA who i can also get wanted $400 more per month which at the time was 3X more than what i was paying!