So I was bumming around in Rockport, MA and I saw a camera shop. OOOOO!!! CAMERA SHOP!!! Anyway, I bopped in and struck up a convo with the shop owner who was very pleased to see I had a D300 but HORRIFIED to see I had a non-multicoated CPOL on my camera. He explained to me that it was "wrong" and simply was not going to give me what I needed, and that I needed one of these $200 ones over here. Now... 1. Clearly the dude was a salesman, so I can't take anything he says without some caution. 2. Clearly my Promaster CPOL works... 3. I strongly suspect how much the dude knows since he considered my 18-200 3.5/5.6 AFS VR "really good glass". I mean, it's a fine lens, don't get me wrong, but "really good glass"? Not. So the question is... how much of a difference is there, if any? What is so great? I thought the multicoated CPOLs were mainly just more rugged, but I have no idea... generally speaking I'm not about to spend $200 on a filter, but... maybe... someday. Any thoughts? Thanks!