I've used the Sawyer the last couple years. Have been happy, but I did freeze it pretty good once, and the bags are well worn. Not sure I am confident I won't tear a bag, and they state it should not be frozen. So, now I don't know if it's really working.

Edit: for under $20 I just picked up a new Sawyer mini.

Last edited by prm; 09/03/15.