I finally broke down and bought a high-capacity water filter. I had been looking at the Big Berkeys for a while, but finally decided to go with the Aqua Rain instead.
For those unfamiliar with them, these filters are the large stainless steel type that look sort of like a large coffee pot or other kitchen pot. They are for stationary use, not hiking. There is an upper pot with the filter cartridges in it, and this nests on top of and drips down into a lower pot that collects the water and has a spigot.
The Berkeys have been around for a long time, and are considered to be great filters. The one thing I was concerned about with them is that the way the upper chamber nests into the lower one, drips or spills of un-filtered water could potentially run down the side and into the lower one that you're trying to keep pure, contaminating the water. You could probably tie a rag around it or something to catch spills, or just be extra careful, but I still wasn't crazy about the design.
I then learned about the Aqua Rain and researched it. The big difference to me was that it was designed with a baffle to divert any spills away from the opening of the collection chamber. Everything I read indicated it was also a very well-considered filter, albeit without the long track record of the Berkey. Some people like the Berkey filter elements better, some the Aquarain. They are compatible and interchangeable if you have a preference for the other brand.
The filter elements are supposed be could for up to a couple thousand gallons, I think, if the water isn't too murky. They're around $80 to replace 2.
So I bought the 2 element model from Amazon for $200. I looks very well made and high quality. I have never seen a Berkey in person, so I can't compare. The only thing that was odd was that there was a strong petro-chemical sort of smell. I finally tracked it down to this rather crude cast rubber ring that goes around the bottom of the base, apparently to keep it from slipping or scuffing. It doesn't affect the operation, or have any contact with the water.
We took it on a week-long trip to a remote house with only well water. The well was very suspect, and was thought to have been the cause of a friend's giardia infection some years prior. So we wanted to be extra careful.
The filter worked great, and was easy to use. It has to be disassembled and the elements protected for transport. It also takes a day or two for the elements to be fully wetted and flow at full capacity, which is still at a slow rate of maybe a drip a second. But those drips add up, and overnight you get a gallon or more of pure water.
It works best if you top it off regularly, and would probably make 2-3 gallons a day. We never really measured it because we were constantly using the water from it. But it certainly supplied a surplus of drinking water for our small family during the week we used it.
We were re-filling it a lot, and sure enough some water spilled down the side in the process. So I was glad it had that baffle.
So I'm very happy with this thing, and am glad I have it for survival if needed.
I am happy to answer any questions anyone might have.