I have 3, the older gen 2 caps on mine leaked but was replaced by Cracklin and no leaking after that. Do not over tighten the cap.
My first one is around 10 years old. I tavel long distances with no fuel avaialble and they are used regulary.
They are though, one survived a high speed crash...
Base layers need to be close to the skin.
Will show off your six pack temporary stored as a beach ball nicely if it is your walk around shirt at stops.