I purchased the PC600 one month ago and followed the set-up instructions to the letter.  The only particular problem I experienced was that the pre-filter kept leaking around the threads between top and bottom halves of the filter housing.  It took about 5 or 6 attempts tinkering with just the right amount if tightening and copious amounts of plumber’s grease around the “O” ring to finally attain a leak free seal.  Aside from that, I’m very pleased. My water is crystal clear and has no smell what-so- ever.