If you maintain this bottle well (study the quirky instruction manual, this thing isn't cheap!) it will do better than just about any other product on the market. I say that having used many others and having witnessed lots of other products fail in the silty and highly contaminated environment where this one succeeded for me--and it has continued to succeed for a long time. I used it for two months in the Bolivian Amazon (as well as two of my friends...on the same bottle!) and it supplied ALL of my water (~2L/day for me and up to 6L/day in total) and didn't require more than a couple of rinses of the dirty water portion while in the field. My field work supervisors were shocked that it worked so well as they had long since given up trying to use pumps of any kind in this location due to the clay and silt. Instead, they boiled all their water, which resulted in just-as-silty, brown and totally flat (and when done on a camp fire, smoky) but potable water. I'll admit to being lax on maintenance the first two months, but I've since come to understand the necessity of keeping the o-rings greased and free of debris and my bottle is working as well as day 1.
--Can filter just about any water source and maintain performance (though the life of the cartridge will lessen).
--Has a very high flow rate so filling other containers is fast.
--You can use it to store water as well.
--Air-tight cap means that when it's sealed it's safe from contamination even if it falls into a river or on the ground.
--One of the lowest prices/L for filtering solutions if you plan to actually use 4000L within the two-year life of a cartridge.
--Dirty water fail-safe means it'll cut off flow before you can drink inadequately filtered water.
--Each cartridge is good for two years from when it is first opened. This is due to the makeup of the filter which ships with a glycerin coating that is removed when you prime the bottle for the first time. So once the clock starts ticking, that's it.
--The carbon filters only lasts 250L (though this is A LOT of water). But if you're using it as an actual bottle then your saliva can contaminate the carbon which means if it sits after you've used it (less than 250L) you'll need to change it out the next time you use it. I avoid this by using the bottle only to fill other bottles for storage of clean water.
--The care instructions are not written/edited well but they are crucial to figure out. This may be a problem that no longer exists (I believe I have an earlier generation of the bottle) and there are instructions online.
--Learning how to use the bottle (and, especially, teaching others) can be a bit frustrating and there are a few too many ways to contaminate your bottle if you're not careful (or a friend is not careful). For example, forgetting to completely empty, replace the bottom, and then pump 30x before removing the top cap before switching out the carbon filter can contaminate the bottle. Other annoyances include needing to do front-side washes (put water in the dirty-water end, swish around and dump back out, or remove the cartridge and soak), lube the internal pump o-ring, do membrane integrity checks (i.e. make sure the bottle will continue to flow in all directions once it is pressurized), and lube the base o-ring.