Has anyone tried a "Buff" as winter headwear?

[njHiking.com]

The have a Polartec one for winter, and it seems much more versatile than a regular knit cap. I was curious if anyone has ever tried one, and if they liked it. You can see what a Buff is on their site, and a quick video really explains it best here.

They even have them for dogs... not sure if a dog would enjoy it, but the adorable factor is pretty high.