I bought one of those and while it's interesting that I managed to ride with it for a while without cooking alive, my arms ended all sweaty and stuck to the fabric. Since the rain isn't so acidic that my arms will melt in it, I imediately thought it would be way better if it had short sleeves. Imagine a rain shirt instead of a rain jacket. There seem to be quite a few products called "rain shirt" but they seem to be for golfing and low intensity exercises + they don't have the vent holes this thing has.

This one would actually be quite good for motorcycling.