I like this product a lot for two reasons; firstly it totally stops my visor misting. I have a pinlock insert in my helmet which stops my visor misting except from on very wet, cold days where it mists up a little. The combination of the pinlock insert and respro foggy means a totally mist free ride. Secondly, I like this product because when it's fitted the air I breathe in is fresher as it acts as kind of a snorkel drawing in fresh air from outside of the helmet. Before I fitted it the air I breathed when sat at traffic lights was the warm, CO2 rich air that I'd just exhaled, nice!
The only downsides to this product that I see is when taking the helmet off. Putting the helmet on seems easy enough but removing it is a bit more tricky as the mask folds inwards and the nose piece scratches my forehead. However of I pull the mask away from my face with one hand and remove the helmet with the other this alleviates this issue but takes a bit of practice. A small price to pay for fog free vision.