It's not so much about the voice you talk to, but how willing they are to pay up when you need them. Do you want your car fixed by people you choose, using real OEM parts, or by the company that Geico contracts out to, for example. The cheaper places manage to keep their rates lower by saving money elsewhere.
Also, Geico will send your rates through the roof the first time you get a ticket. In the industry it's known as being "off to see the lizard."
It's also worth noting that a good agent can find you discounts beyond what your initial quote is.