On another unrelated note, I noticed that the Berkey Filter Elements need to be primed, and they suggest doing this with pressurized water (from a faucet). There is an alternative priming method, but it appears to be much less effective.

This makes me start to consider other methods of water purification such as Slow Sand Filtration.

I, too, have a Berkley filter and like it. The one I bought is the stainless steel one with four black filters. I wanted a way to filter water that didn't need power, and the Berkley's reputation was what sold me on it. I use it every day.
I also got the Post Filters for it, mainly for removing fluoride. My city, like many municipalities, adds fluoride to our water to help our teeth. After reading many doctors and dentists warning about fluoride, it bothered me enough to do something about it. I'd recommend doing a search of the health consequences of having fluoride in your drinking water. Quite a few doctors are saying fluoride is more toxic than lead, and slightly less so than arsenic. Read your tubes of toothpaste - the part where is says don't swallow this stuff - and if you do, call your local poison control center. Just what you want to mix into your kids Kool-Aid, right?
I went to one of our city council meetings to bring this to their attention, armed with many notes and petitions from doctor/dentist groups and ask that it be stopped, only to be told by the lady with the ugly glasses that their documentation proves it's safe. She asked me if I was a doctor. I said I wasn't, but that I did know how to read. I, again, tried to show them the petitions I brought, only for her to reiterate how safe fluoridation was. I said to her "So I'm supposed to believe a politician over some thousands of doctors saying just the opposite, huh?" After a few seconds of silence, I just walked out.

We are truly led by idiots!