I've had trouble with my Sigg bottles. They started to leak and the outside coating started peeling off! To me this is actually a health concern, cause if there is a leak then the inside coating is no longer intact! And aluminum, they say, is linked to Alzheimer's...

Another problem was with the lid. I never really liked it: on one bottle the top from which you sip was too tough to open, on the other it wouldn't stay open so one had to hold it with teeth as one was trying to drink.

So I am sticking with plastic for now. Yes, I know, it's probably linked to Alzheimer's and the like too.