I've read all the prior 7 comments, and I'll try to address some of the complaints (that I found rather unfair). This purifier bottle (when filled) is a tad heavy, and it remains weighty after squeezing out the usable water, because the filtering system (3 stages) remains inside of the bottle, and the filtering system also remains wet (hence a bit heavy even when the bottle is effectively 'empty'). The weight did not bother me, as I was grateful not to be lugging around 20+ liters of bottled water. Regarding the taste, yes, there is a noticeable iodine taste, but that is the point of having an iodine stage filter -- it's a virustat. I much prefer the rather mild iodine taste to getting a stomach full of nasty bacteria/viruses. If you cannot stand the taste of iodine purifier systems, then the only real option is to load up on bottled water -- a rather impractical task (and possibly dangerous) if you are in the middle of nowhere. When assembling the bottle, do NOT throw out the paper inside of the bottle until you remove the first-stage filter -- you will find a charcoal filter (i.e., initial stage filter) wrapped inside of the paper. (I nearly threw it out, but thanks to a below comment, I unwrapped and located the filter. NOTE TO KATADYN MAKERS: please improve the packaging so that your buyers don't toss out the wrapped up filter!) Regarding the pain of priming, yes, you must prime the 3-stage filter -- it takes time (if I recall correctly, it's approx. two bottles of water squeezed out, and then a few hours of full-bottle sitting). Priming is required in all water purifiers that I know of...including home Pur brand water purifiers that need to have water run through it before use. If your circumstances permit, try priming your bottle before heading out to the backwoods. I was able to prime before leaving home -- this kept my filter stages wet and primed before dipping into skanky water. Another random note -- when your bottle runs low, you will have to squeeze harder than when the bottle is full. I think this hard-squeezing is a reasonable expectation, given that you are squeezing a smaller volume of liquid through a 3-stage filter. If the filter clogs up (which mine eventually did after about 20 refills), have a replacement filter kit handy. I found the clogging reasonable, given the amount of nasty stuff in the water I was filtering. (I read a prior comment criticizing his/her Katadyn crapping out after two days...well, if the water source is dirty, then, yes, the filtering system will clog up. I would have liked to have been able to reverse the flow direction in order to blow out some of the gunk, but I'm guessing that this would be nearly impossible (and possibly unhygienic) given that tainted liquid may end up on the wrong side of the final-stage filter. Bottom line: I used the Katadyn system per directions, and I kept hydrated and did not get any gastroenterological illnesses. I was truly amazed that such a product exists in such a handy form factor. If you want high volumes, then you'll need to stick with the big pump filters. For mobility/backpacking, this is a great purifier.
