[MikeBVaughn]

I'm genuinely curious about this. What about non-granular-carbon filters, like the sub-.5-micron extruded ceramic-and-carbon pump filters from someone like (the non-Microsoft) MSR? My understanding is those were significantly different from Britta-likes, and were generally a solid choice for deep backcountry backpacking stuff. At least that was what I used doing 40 miles on Isle Royale's interior trails, where nearly 100% of the readily accessible water is wicked-nasty non-moving water, with giardia and cyanobacteria blooms.