for very bad water, after filtering it with a sawyer, drops could be useful I suppose to target viruses, then I think you can just use bleach though since all the larger organisms have been removed by the filter.
Also, for trips over 3 days you should probably bring the 60ml syringe for backflushing if you want to actually reach the rated life span of the sawyer. That adds about 35 grams.
Jake D, exactly, aquamira has a lot more room for error and failure, you have to measure it right, mix it right, let it sit right, then pick the right time/temp combination, accurately, every time, so it's odd seeing its weaknesses noted as a strength. The holes in the sawyer are physical, ie, they are I believe 0.1 micron big, period, unless you freeze it, but how hard is it to not freeze something if you are aware? Not very. Put in sock in sleeping bag at night, end of story.
The sawyer is easy, fill bag, attach, let drip into clean water, drink. I'm glad I don't care about a few ounces for stuff like this, heh, makes the choices a lot easier in terms of using good tools.
The strength of poison drops is that if they are used properly they kill everything, which does matter in some cases, none that I've ever come across, but I'm sure it's valid in certain situations.