I bought a 'Leatt Evaporative Cooling vest' just before the raining season when there wasn't any Windchill effect , in fact just the opposite (heat Index) was boiling my brains on rides. I really struggle with riding in that Heat as your riding into Hot Air. I suspect most people just have a few months off at that time. They Seem to be a bit cheaper than Rev'it and made from the same important material 'Hyperkewl' or something. It does work but it feels a bit strange like your covered in wet liver or something and there's that Cooling sensation like being covered in Cooling powder. I suspect it would be better over a microfibre Tee.
As soon as the rain season started and the Humidity started to climb I got prickly heat after using it, so it's definately only effective in the real Hot Dry Season.
I think the neck thing would be very effective if you was to choose just one product.
If your only going to use it for a couple of months a year , it should last for years and years and so is value for money in my book.
I suspect if used on a strenuos Offroad trip at that time of year it would be great. you could just re-soak it after an hour or so from a stream or bottle of cool water from a Fridge.
