I haven't had the thing very long. I've only had a few days out shooting with it. It works as described. I have a Canon 400D/XTi which is a cropped frame sensor so I can't comment on vignetting on a FF body. It didn't vignette on a 1.6 sensor w/ the Canon 17-40mm L or the 24mm TS. It seems well constructed. I didn't have any problems with flare so I don't understand why you would pay a lot more for the multicoated. I use a step down ring and use the filter on multiple lenses. Its seems pricey but its still a deal compared to the multi coated filters. I'm not sure you wanna go cheaper than this anyway.