Buy whichever you want, BUT buy them from a no hassles return policy.

I bought something than the top of the line CPL and tested the impact on focus and sharpness - lets just say I tossed away the filter and the few dollars I thought I saved.

I now test every filter I buy the day it shows up on my two "best" lenses and anything other than "perfect" goes back before the UPS driver leaves the block.

Mike