I love this filter!! When it comes to clean water on the trail, I'm not interested in taking any chances. The Platypus filters 4 liters in a couple minutes. I've put some seriously sketchy water through this filter and it has come out absolutely perfect. Another nice feature is that you can use the "Clean" bag as your backpack water bladder during the day and then hang the rig on a tree at night for your camp water, basically saving you the hassle of carrying an extra bladder in your back pack.