I have always been a traditional "screw on" filter type person, but recently looking at a selection of Cokin filters in my local used equipment store, it struck me that for a couple of hundred dollars, I could have a HUGE selection of filters of all different types; a fraction of what new glass would cost. My question: From experience, what are your thoughts on Cokin filters? How do they compare to their glass counterparts? I'm all for saving a buck, but not at the expense of the quality of my photographs. Any advice, experience etc greatly appreciated.