Hi, thanks for the replies. Well the reason why i asked the question was because yesterday it started out as an overcast day, but after the clouds passed it became sunny. Shooting with the polarizer and the sun to my side, the blue sky and clouds had a very dramatic look to it. I guess on an overcast day its better to go out and shoot, and find out for yourself. Really that is the only way to do things anyway. Also the thing about colors becoming more saturated was something i read off a site. I dont think opening up a stop would make that difference, but if you careful not to include the sky, colors would stand out more, rather then becoming saturated. Or maybe theres a filter out there that will take care of that for you.
Sorry for the long post.