i bought this MSR filter back in 2008, i've taken it on 4 multiple month long journeys and many day hikes and treks in between, and it still does it's job well. it's simple, as long as you follow the instructions correctly.
the filter itself is ceramic, it comes with a scouring pad to clean it, and a measuring device so that you can tell when the filter needs to be changed. be sure to let the filter dry out between uses by leaving the lid off and hanging it in it's mesh bag for a while before you pack up. i like to strap it to the outside of one of our packs, careful to make sure it isn't swinging.
the pump is hard plastic, with a rubber hose that hangs down into the water. the end is capped with a large particle filter piece to keep sand and grit out. a 1liter water bottle screws on to the bottom of the filter, but it's not a necessity to make the thing work.
it's hard work pumpin' that water, but considering how fast you can sip some pure clean H2O, i'll take it. if you have a lot of water to pump, switch off with a partner, makes the job go a lot quicker. if you have a steady pace you can pump a liter in 4-5 minutes, quicker than drip filters. it's built pretty tough, and easy to maintain.. the entire thing comes apart to be cleaned or replace parts.
to buy the pump with a filter cartridge is $70-90, and replacement filters are $30-50. supposedly one can pump 1000 liters through a filter before you need a new one, it if is properly maintained. i have yet to need a replacement filter!
i love having a pump that allows me to drink the water fresh and cool.. one of the best experiences with this filter was pumping some near freezing glacial stream water on a hot sunny rocky mountain hike. or bringing the filter into a cave in Tobermory just to say that we drank fresh cave water!
