For what it's worth, I use an MSR microfiliter only because I couldn't afford the platypus at the time. My system works great albeit with the limitations already noted (time to filter, backflushing, etc.). It's a much better system than the hand pumping which has been mothballed in my downstairs camping storage area  :) The platypus is definitely the cadillac of water systems but that's just my opinion.

Iodine tablets used to a method of choice but had to move away from iodine-treated water. Chlorine tablets are handy but can be expensive if you filter a lot of water, especially over a 5 to 10 days of a trip (depending on length). I even used to backpack a small nalgene of bleach and an eyedropper more years ago than I care to admit  ::) That had too much of a potential for disaster inside my pack too!

Thumbs up to current technology on this one.