Instruct: Classify Amazon reviews into positive or negative sentiment
Query: AVOID AT ALL COSTS!!! TDK DOESN'T HONOR WARRANTY!

I swore by TDK disks for the last 3 years. They were rock solid. However, the last set of 100 I bought were terrible: I tried 10 from throughout the package and they were all bad. What happened was that TDK disks were made by CMC Magnetics or Daxon. Now they are made by Ritek and they are junk. Worse yet, when I contacted TDK and asked them to replace them they told me a great story, but I never got the replacement disks. The problem disks were tested on a Plextor PX-755SA (a premium drive) and a Plextor PX-850SA (actually manufactered by Lite-On).