I was testing my newly arrived polarizing filter (Fotga, $10) with my 55-200mm lens. The result didn't turn out that I was expected. Loss of detail, vignette at corners and
it was horrible. Then I took the same picture again without the filter and details are way lot better.
In short, cheap polarizing filter does not fit with zoom lens and best fit with wide angle lens.
The picture above is shot in raw and post-processed with high-key settings.