357gm? That's about 12.6 oz. A Nalgene bottle with a titanium canteen cup weighs about 10.5 oz, which only about 2 oz less (although a standard Nalgene holds 1.0L where as the flask only holds 0.6L. Still the stainless would be really strong and the size is nice for EDC. Plus, it has a really high cool factor.

The cost for the Sigg flask & cup is about $30.00. The cost of a Nalgene on sale is $5.95 + the titanium canteen cup is $30.00 or about $35.95. The Sigg looks good.

Has anyone had any rust problems with stainless steel drinking vessels?. For EDC use, I'd be a little worried about rust even with stainless steel. I have a stainless double wall thermos (no rust problems), but I rarely use it for more than a week at a time.