I use a dark visor in the summer, and a tinted one this time of year. I find the dark visors are too dark for this time of year (and yes I know they're not kosher as regards the law). Having had advice from the horses mouth (PC Williamson), even he said he's not interested in someone wearing a dark visor, unless they're stupid enough to ride at night. The primary visor must conform to the law, but the inner visor (whether it be an insert or secondary visor) can be as dark as you want. The secondary visors in most helmets distort your vision, I find. Caberg, for example, used to give me a headache. The dark inserts are a good idea, but need to be squeaky clean when being fitted. So it's not something I want to be taking in and out all the time. My answer is to always carry a clear visor with me. It's not a faff to change over, only taking about 30 seconds on a Shoei. Visor bum bags, or stashing it under your seat, would seem to be the answer to me...