They do let a little more sediment through and they are not as good with Whirley-blade type grinders as a paper filter. We are satisfied with city water run through a series of 2 carbon activated filters. It removes chlorine taste and other bad odors but retains the minerally taste of the water. We don't recommend soft water or distilled water. So the ideal brewing water is bottled spring water.
Soft water can make all coffee taste dull, effectively muting the good bright flavors in a cup.
Its a very disturbing thought to those of us who want to get the most out of the coffee we roast. Ideal water temperature for brewing is 195 to 200 degrees. Bring your water to a boil, wait at least 1-2 minutes, and brew. The rule is 2 level tablespoons for a 5-6 ounce cup. Well, actually I do.