i kinda liked the SIGG bottle for a while, but i saw the downside with them being lined, and then getting dented.
i preferred the kleens unlined SS, they can take a beating just fine, but never bought any.
my answer has been to limit my exposure by doing things like never heating food in plastic, esp. the micro. i dont make "ziplock food" and other various things that i think are easy to avoid. in doing so i feel just fine about the trace chemicals i may be getting from something like nalgene, IMOP if i can largely eliminate my exposure to many things the couple i willingly subject myself to will keep me well below the"average" consumer.
this has been my motto for almost everything in life, control the things i can so the things i cant dont affect me so much.