What I like:
I like filtered water when the source is not clear, as opposed to tablets only
Lghtweight, 7-8 ounces
It’s easy to pump
Reasonable volume per pump
Fits on a Nalgene bottle, weight is 7 oz if you pump into a Nalgene and don’t need the second output hose
.3u filter eliminates Giardia and most other critters
What I don’t like:
Uses special filters (treated paper) each good for about 50 – 100 liters which are difficult to find
Getting the filter in takes a little dexterity