There are a few revered water filtration products out on the market and the Katadyn BeFree absolutely holds its own amongst them. It is lightweight, it is a simple scoop & drink process, and both the bag and the filter cap are replaceable as parts.
The manufacturers claim it is effective against 99.999% of micro-organisms including giardia.
It is particularly impressive in its rate of output - it's flow rate as it pertains to drinking directly from the unit. It claims to be effective for 1000 liters of filtration - put another way, it is effective for roughly 333 days of 3 separate liter fills. So for most of us that's a few years worth of use.
Having used this I was quite happy with it - until it burst. A tiny pin-prick of a hole that I couldn't figure out how it happened, but a puncture regardless. Another issue I have is that the bladder when half filled can be difficult to store upright, for example in your water bottle pouch on your pack, as the weight of the filter sags the pouch downwards and it loses balance/stability.
Other than my puncture though, I found (find, as I have a new one) this to be a good product with great waterflow.
Specifications
Dimensions: 10.5"H x 2.5"W x 3"W
Weight: 2.2 oz
Materials: EZ Clean membrane, BPA & PVC free
Price: $49.95
Pros and Cons
Pros: Light, fills easily, cleans easily, great water flow.
Cons: Durability & storage.
The Final Score
7.5/10 - Durability was an issue for mine, but hoping my second one lasts longer.