Here's an example of a shot that I know was shot with a protective filter. I had filters on both lenses for this shoot because it was raining intermittently all evening. (And I can also see the additional flare in some of the other files.)
It is probably not as sharp as it could be, but that is nearly always the case, not just because of filters, but more due to capture skill. Still, I don't think most people would call this one soft. I do not remember for sure which filter this one was, but I think it was a Hoya. Attachment#1 (jpg file)
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!