I have been using the Katydyn Hiker pro for years and really like it for dependability. It is a little heavier than I would like though. I used to drink out of springs without purification to until eight years ago when I got Giardia. I don't want to go into the details, but trust me it is something that you never want to experience. A lot of times springs actually come from creeks and lakes sometimes miles away. It may look like its a clean pure spring, but it could be coming from somewhere else. I second using a filter also around any area that has or does contain livestock . The cattle can spread some pretty nasty things into areas that look pristine but have been compromised. The biggest thing I don't like about the Katydyn hiker is the price of the replacement filters. They are very proud of them.