Ok, having actually tried it a little, I can't recommend the MK Granite Creek Windshirt for serious use unless you get it as cheap as I did. I paid $15. It's worth $15. It's probably worth more than $15. But it weighs ~9 oz and isn't super breathable, you don't want to wear it during strenuous activity. I plan to primarily use it as a light, nice-looking shell when I want to do things around town in bad but not super bad weather. I think it will do very well in the role that I intend to use it for.

Don't take it backpacking.