Pros: (*) Field serviceable ceramic element lasts and lasts
(*) Heavy duty construction
(*) Elegant design
Cons: (*) Heavy
(*) Doesn't include a water bottle attachment
I work diligently to keep my pack weight down because I enjoy the trip more with less on my back. Still, this water filter is one item that I refuse to compromise on. The Katadyn Pocket Filter (http://www.katadyn.net/katadyn_pocket.html) is rated at one pound ten ounces, but it just weighed in at one pound thirteen ounces on my home scale with the included pouch and the field repair kit.
The reason this filter weighs so much more than other filters is its hefty construction. The housing consists of aluminum end pieces with a plastic center housing. The end pieces easily unscrew for access to the ceramic filter. I won't bore you with more details that you can get from the manufacturer, but the filter is rated to remove the standard range of contaminants.
This filter is easy to use. Take the filter out of its handy travel pouch and connect the inlet and outlet hoses. Drop the inlet hose in the water supply and clip the outlet house to your water bottle or water bladder. The filter doesn't come with an adapter, but there are adapters available for most types of water bottles and water bladders. I always just clip the outlet hose to the opening of my water bladder. The pump handle is comfortable and is long enough so that excessive force is not required. The Katadyn Pocket Filter is rated for 1 liter (1 quart) / minute. This is accurate unless you are pumping really dirty or silty water.
I took this filter on a 11 day backpacking trip around Mount Rainier last year and am preparing to take it on a 8 day trip in a few weeks. I like this filter because I feel certain that it will not fail on me. Most of the cheapo plastic filters out there do not instill me with the same confidence. I used this filter to filter glacial river water. Glacial river water is the nastiest water you can imagine. So full of silt and minerals that you cannot drink it. I was able to filter several liters of the stuff using this filter. I had to stop and clean the ceramic element several times during the process, but remember that many filters out there are not field serviceable...when they clog you have to buy a new element. On my last trip I added chlorine to the filtered water to get rid of any viruses since this unit is not a purifier, but I think I will skip that step this trip and just filter the best water I can find.
I recommend that you build room into your weight and money budget for this filter. I can't think of anything more important than a reliable source of drinking water.