I used this water filter system while living out in the country with only well water available. The water was very dirty, but the zero filter's worked well and got all the particles out so I could have clean drinking water.  I had to replace the filters sooner than normal because of all the sediment in the water, but was glad to have a system that would allow me to filter the water instead of buying bottled water. The filters are easy to replace, which is really nice.
I have used this system with city water also and it worked great. I can really tell a difference in the water from the tap vs the water from my zero.  I will not every be without this system, no matter what kind of water I have!