GEICO vs Metlife car insurance

Yesterday, I was reading this message from Warren Buffet. Here he has strongly endorsed buying car insurance from GEICO, one of Berkshire's subsidiary. He claims that close to 40% of consumers will save money by going with GEICO. Given Mr. Buffet's credibility, I decided to try out GEICO. I was pleasantly surprised.

I have been a Metlife Auto Insurance customer for 7 years now. I went with them, largely, because they were the only big name willing to sell insurance to fresh immigrants like me, at a rate that seemed reasonable at that time. This was due to their existing relationship with my employer, Lucent Technologies. Since then shopping for car insurance deals has been the last thing on my mind.

But given the current economic situation, Mr. Buffet's personal recommendation and the fact that my auto insurance is up for renewal, I called up GEICO to get a quote.
The operator was more than friendly, he took all my information on the phone and gave me a quote (in 5 minutes) that was less than half of what I was paying Metlife and the coverage and deductibles were much better with GEICO. Needless to say, I changed my provider in a New York minute. It really amazes me that there is such a vast difference in insurance premiums across these providers.

Either GEICO is taking risks that are too high or Metlife's auto business will be dead before long. For now though GEICO rules. The skeptic in me wants to look deeper at GEICO and see if there is a catch.