It's funny, I've been taking pictures for a while now (really since 1987) and only recently have I started experimenting with circular polarizing filters. When I see a photo like this, with those deep blues and those big puffy clouds, I see the benefits and I'm hooked.
This image was shot on the top level of short term parking at Nashville International. Aside from just a slight tweak of the color balance and the burning the edges a bit darker, this image is straight out of the camera.