One of the problems with reverse osmosis water, and much filtered water, is 
that fluoride is one of the chemicals filtered out.  We put a filter on our 
kitchen sink that just filters the chlorine taste.
And I know everyone says that the French Press makes THE  coffee, but you 
will also read that the French Press and boiled coffee, both of which are 
unfiltered, raise cholesterol, and are not  recommended for that reason.