This isn't a comparison of filter brands, but I wrote this in response to someone else asking if brand matters:
The reasons to buy good filters are pretty much the same as the reasons to buy good glass:
Good filters are neutral in color and won't add a color cast to your picture.
Good filters are well-shaped or more perfectly flat. They won't add distortions to your pictures.
Good filters have coatings that will allow more light to pass through, and/or reduce reflections. They will greatly lessen the chances of flare or glare or reflections in your final image. (Note, look for Multi-Coated lenses. Considering the same brand and size the more money you pay just about always goes toward the coatings, and every coating has a purpose. All of those purposes are geared towards lessening the bad light and increasing the quality of good light that hits your sensor/film.)
Good filters have better things about their build. Perhaps thicker frames, perhaps better threads, better knurling, perhaps better anti-reflective paint. (I recently had to get a step-up ring and B&H and Adorama were out of the $7 General Brand rings I normally buy. I went local and had to buy a $20 B&W ring. It was quite a difference from the Generals in all the above points.)
Good filters clean more easily. Last week I spent an hour cleaning 4 Hoya lenses, cursing and swearing the whole time because I could not get them clean. I tried 3 different cleaning solutions, 2 different wipes, 2 different microfiber cloths. I went to the camera store and bought $37 worth of cleaning supplies - all different - in order to find the best way to clean my lenses and filter. Well today I saw a message stating that Hoyas are notoriously difficult to clean, and B&W is better. I don't know if that's completely true, yet, but my next filter will be a B&W.
The more you pay the better the coatings, the better the frame, the better the glass, the better the anti-reflective paint, the better the knurling, the better the light and less glare, flare, and reflections.
So buy the best you can afford.