The battery-operated clock let me know it was time to replace the filters. I ordered them on-line and it only took a few minutes to replace them. I like the reminder. I like that they're color coded.
I went to this system after having a GE two filter under sink system. I like the fact there are 3 filters and have been very happy with the quality of the water. After a filter change, it does take quite a bit of water to flush out the black carbon, but not necessarily more than any other filter system. The only real complaint I have is that the water flow seems extremely slow. It takes quite a while to fill a coffee pot with fresh water and in the morning when caffeine is desperately needed....it takes to long!
Pros: Clean taste, Easy to install, Long lasting filter