Houdini jacket - what do you use it for?

I tried running with the houdini jacket in about 5 degrees Celsius and it was one step removed form wearing a garbage bag - it doesn't breathe at all. Me and the jacket were coated with sweat after.

I can't imagine using it for anything of even moderate intensity.

For me it'll just be for walks around town or mild hiking.

What do you use it for?