Here is a comparison of two images taken with my Phantom 4 — one image with the Polar Pro polarizer, one image without the polarizer. These are RAW images, no editing on either images. Both images were shot in manual mode on the Phantom 4. Looks like some lens flare in both photos, although I might have had a smudge on the actual lens, oops.
With the Polar Pro Circular Polarizer. ISO 100 - f/2.8 - 1/200
Without the Polarizer. ISO 100 - f/2.8 - 1/227
If you have any questions, feel free to reach out to me on Twitter @iCrizzo.