I have to agree that metal water bottles are probably a fashion statement, but I have four stainless ones. I may even wrap them in twine someday to take it up a notch.

I don't like the taste of plastic. I'm never in too much of a hurry to pull over for a drink. Stainless does not have a liner (aluminum does). They wash easily. They are puncture resistant. (I had a plastic water bottle punctured by a dog bite while riding... I was glad it wasn't my leg).