I am a big fan of Better Bottles but I have stumbled upon one minor flaw. The have an oilcan effect. I went to raise the bottle out of my swamp cooler and the liquid in the airlock thingamajig got sucked back into the wort. DOH, and of course I dont think I used sanitized water in the airlock.
I won't go back to glass bottles but i will remove the airlock before lifting ( nah, I'll forget again).