I started out using Aqua Mira on the Appalachian Trail, and switched to Polar Pure. It's easier to use. And so much easier, more reliable, and less bulky than a pump. I used it a couple times a day almost every day for several months, and it never ran out. Slight iodine taste, but it doesn't bother me much. I carry a nylon stocking for filtering out floating particles when collecting water.
This review was written in the old system and had content requirements that are different than reviews written today.