I tried to use one of the filter bottles a few years ago. The problem was I couldn't suck enough water through the thing to get a good drink. And what water did come through tended to go right down my throat which, in sucking mode, caused much choking and coughing. It was a cheapie. Maybe the newer more expensive ones are better. I saw--but can't locate now--a new one a few weeks ago where the filter fit in the bottle like a piston. You filled the bottle, then pressed down on the filter to express the water through it. A little pricier than the regular filter bottles at about $70, but would be much lighter than carrying a quart of water for an all-day trip.