I have used the Platypus and its very durable but you'll NEVER get it in an altoid tin <img src="/images/graemlins/smile.gif" alt="" />. I have used the gerber bags and they are the best seal I have seen. I just wish they made a one liter bag. I have also used condoms and qt sized Ziplocks. Ziplocks are nice cause theyre almost exactly a liter. I suppose my ideal bag over all would be a 1 liter gerber bag.