precisely my point! i broke one filter because of too much screwing action that i dropped the filter onto the hard floor and it was smashed.
Even so, I would not leave the CPL on full time - it would cripple the camera's performance and give you all sorts of strange effects unless you are careful. I certainly would not want to miss shots because I have to dial in a higher ev, or even worse, because I am busy turning the CPL to get light coming in at the correct angle.