I used the Clearaudio outer ring and centering spider for years on my Clearaudio Champ II. I would say it worked to keep records with slight warp flat. I don't use it anymore. Sold it. I haven't missed it and wouldn't spend more than $100 to buy another. I don't think it made any difference in sound quality in my system. If it did, it was so incremental that I didn't notice. Warped records is certainly not the weakest link in my sound chain.
