I have had my Royal Berkey for awhile now. The biggest surprise about these is that to "prime" the elements you really want to have clean water that comes out of a faucet. Kinda like how you need a knife to open a knife in one of those crazy plastic packages the Gerbers come in. I guess you could do it with some sort of a squeeze bottle or something. Also the unit is really big. I read the dimensions but maybe didn't fully grasp how big the thing is. It takes up a lot of room in the kitchen.
Also you need to periodically clean these things out. I noticed when I was pouring water into the top part that it was kinda gross. I took the filter elements out and washed then rinsed out the whole thing. In hindsight I recall reading somewhere that you're supposed to clean them monthly.
We use the Berkley regularly because the tap water we get is pretty nasty. Also it will be useful for brewing. For someone who wants to regularly filter water in a stationary position these things are great. Just pour the water into the top and wait a little while.
I am glad I purchased the Berkley. It looks nice and sits in our kitchen. I use it to fill up a couple containers of water we keep in the fridge to drink from. A great preparedness item that also has a valuable everyday life role is a hard thing to find.