well to add some closure to my OPINION of filter vs no filter, I have been doing lots of comparisons. I came to the conclusion that the cheap filters are absolute junk (i knew this from the forum, but was calibrating my eye to the symptoms). I just got back from taking some using my cheap CPF (sunpack) and that made the decision. The distortion is so bad it looks like i missed focus! It makes it hard to cough up the coin for good ones after seeing how bad the cheap ones hurt the quality. The good ones would have alot to make up for in order to be acceptable IMHO. I didnt have a tripod so my methods today werent the most scientific but if anyone wants to see the difference I can put up some samples.
I will not be using filters (at least until i get some b&w's) because while they may protect the lens (or reduce glare in the case of a CPF) the ruin the clarity. What is the point of protecting a lens that wont take clear shots with the "protection" in place. Anyhow, I know most dont care base on the feed back earlier in the thread, but thought I would post a followup.