Polarizers, Circular or Linear?

Most everything I have read on polarizers recomends the circular, but reading an article in Popular Photography has me wondering? This month's issue (April 2009 page 46) "Tips From A Pro", says he prefers the linear but that "it can throw off Your DSLR's meter and auto-focus, be diligent about checking our exposure and auto-focus". So why is it worth all the possible problems? Is there some benefit to a linear polarizer over a circular? I currently use a circular but now am wondering if I am missing something? Thanks

I have no idea why. The only "benefits" to linear polarizers over circulars are that they're cheaper and, possibly, they'll pass a bit more light. But if you wear polarized sunglasses they'll black those out as well as potentially messing up your AF (and for the same reason).