I tried one of these. I do not know if it was this exact brand, but it was the exact same concept. It did work great at stopping the faceshield from fogging up, BUT it did weird things to the colors. Somehow it created a prism and separated the light. It turned the sky a pinkish/purplish color and changed other colors too. I thought it was too distracting, which made it more dangerous and not worth the anti-fog. Those are my 2 cents.
hmmmm
Conclusion
The Fine Vision is an excellent anti-fog system – certainly the best I’ve tried, although I’ve never used a Pinlock. It's quick to fit and unobtrusive, and above town speed it works brilliantly. You don’t need to worry about constantly re-applying a spray, just fit and forget
he has never used pinlock...imo pinlock works best, so not sure what he compared it to? maybe the only thing he knows is some crappy chemical solution that eats away your visor entirely. Well that DOES stop the fog..