Over the years I've found that different lenses respond differently to filters ... sometimes even an high-quality (expensive) filter has an obviously negative impact on image quality.
In years past I used UV/haze filters, graduated filters and polarizer filters all the time ... and I even tried a completely new set of expensive filters earlier this year after a strong recommendation from another photographer I know.
However, whenever I use filters I continue to run into problems that can only be attributed to filters screwing up the image.
Lenses are designed to capture images as accurately as possible without the need for filters. If you add a filter you're just "polluting" the optical design with an additional lens element.
I understand the argument that "a filter protects the lens from damage" but I've found that to be nothing more than a false sense of security. If you drop your lens on the front element with enough force to break the filter you're going to damage the lens ... I've had it happen to me before.
The only thing that I've discovered that
really protects the front element is a strong/rigid metal lens hood or a very thick plastic hood. Hoods provide much more protection than filters (adding several inches of metal or plastic protection rather than just a thin piece of glass) and don't pollute the optics.
The only way that a hood won't protect your lens is if you drop it (front element down) on a sharp pointy object that is small enough to fit inside the hood (like the pointy end of a screwdriver or an ice pick).
Since I don't drop my lenses onto screwdrivers I've never run into a problem that my hoods haven't protected me from.
IMHO, the only thing that offers more protection than a good metal hood is a lens cap ... and if you leave your lens cap on all the time it's hard to create impressive photos.