I was very disappointed in the Iceburg vest. The only time I felt it cool me was when I took it off. I used a mesh jacket, then a long sleeve tee-shirt but neither way did it help cool me.
It may be the fairing of the motorcycle does not let enough air circulation. Bottom line is I wasted my money on it.
Used this on a trip to Sturgis from Southeast Texas. The vest was a big help in tolerating 100 degree weather in Texas and Oklahoma. It holds quite a bit of water compared to a soaked T shirt and as a result the cooling effect lasts longer. A wet T shirt is cooler initially because it is thinner and more air flow passed through it. However, in that kind of weather the T shirt drys out in about 30 min and the cooling effect goes away. Soak it in the morning before starting out and keep it in a plastic bag before use.
I bought this vest for use both on the moto and mountain bike. It does work as advertised as long as there is sufficient air flow. So, it works better during a moto than a slow climb on a mountain bike.
Also, the vest gains considerable weight when soaked and feels "wet" when wearing. This is not a bad tradeoff per se IF the outside temperature is hot.
The other caveat on this vest that took me time to adjust to was that you feel a little "trapped" in it. It doesn't breathe well compared to a jersey for example.
So, if you're willing to accept these shortcomings, you'll be happy. I have used it in hot 90+ degree temperatures and it made riding bearable.