The best water treatment depends on the location and your hiking style.

I use a gravity filter when I know I will be getting some water from an undesirable source. But, it is a lot of work to set up and take down for just a quart. I tend to filter at least two quarts at a time with the gravity filter.

Most of the time here in Colorado the water is clear enough that treating is OK. I did a hike in July where we crossed a stream about every half mile. I could pull out my quart bottle without taking off my pack and harvest a quart, then treat with a clorine dioxide tablet.