Berkey Filtration System

Just wanted to see if anyone has used or has any experience with any of the Berkey filtrations systems. My only concern with using them for preparing brew water is the fact that they dont filter out all the minerals, thus making water adjustments a little difficult. Thoughts?

http://www.morethanalive.com/Berkey_Water_Filters

Looks like an overpriced water filter to me. I use the Model 77 from these people.
http://www.purewaterproducts.com

Had it for years, it’s still on the first filter cartridge. You’re supposed to change filters yearly, but as long as the water tastes good and the flow is good I’m not worried. I do take it apart and clean it once a year or so.

I still use five gallons RO with two gallons filtered water for beer. A carbon (or ceramic) won’t touch alkalinity. Doesn’t filter nitrates, either. Just kidding, that would be RO or distillation.

HA! I think I'm getting an RO system. I've been looking at this one mostly because it looks easy to install. (youtube videos showing you how)
http://www.waterfilters.net/PuroTwist-4000-Reverse-Osmosis-System.html

The only thing I don't like about it is the filters are proprietary, so hopefully they don't go out of business any time soon.

I've also been looking at a system for the whole house so I was thinking about getting this system for the house:
http://www.pelicanwater.com/water_filter_and_salt_free_softeners_with_UV.php

And this system for under the sink for 100% RO brewing water:
http://www.waterfilters.net/PuroTwist-4000-Reverse-Osmosis-System.html

What do you guys think?