i'm lucky in that the only "wild" water i need to filter is the stuff i canoe around on in Northern Minnesota and i only filter if i can see crud in the lake,i often drink right out of the lakes.
so not having any problems i just have that katadyn hiker and rinse the filter after each two week trip.
ok so thats where i'm at on the subject.what i wanted to say is that i have seen the water filter issue come a long way since the 80's when i started with a Coghlans filter that was good to 2 microns,,thats 2 and not .2.
like flashlights using LED's filters have come a long way and i think it would be hard to get one that does not do the job.gravity filters seem to be the next big thing.the issue being price and ease of use.if the water you have to deal with is so nasty i would use bleach after running it thru a filter.
freezing and filters? i would think any filter that froze would be damaged in some way.
as we are on the subject of filters does anyone have any feed back to offer on that small one from China i see on Ebay for just under $30.OD in color and a ceramic cartridge.
Story,a true one..in the Outback a group of sheep ranchers needed water bad but the only water hole they found had a dead kangaroo in it,the horses would not even drink it.
they boiled the water in washtubs over and over with ash's from the fire in the boiling water.let cool it was safe to drink but still had that "dead roo" taste..