Product review (3 stars): They seem to work...
They do seem to help with collection of minerals from the water you use.  But, you still have to pay attention to the scale build up on the heating element.  Do not let it build up, as it is really hard to remove it.  Use white vinegar as least once a week to clean or soak the heating surface.
I also found that as it comes with two pads together; that was blocking the water from flowing into the heating area, so I just separated them and use one pad at a time.