As the least expensive water treatment system in our entire review, the LifeStraw has some obvious appeal. For around $20 you can get a compact, lightweight, and simple system for treating water. It is chemical free, doesn't have any batteries or moving parts (meaning it is unlikely to break), and can last for 1000 liters. It filters out particulate, so you won't be left drinking dirt and grass bits like you sometimes will with a UV light treatment system and it weighs almost the same (2.7 oz) as the Sawyer Mini, which is far less than any pump filter. It is slightly less expensive and is slightly less versatile than the Sawyer Mini.
Source: Outdoor Gear Lab