What you are seeing there is not ringing produced by sharpness but rather the aliasing the image is producing because of added clarity, "0" is the incorrect setting for this TV, it is actually smearing the image at "0" AVSforum has a section in the ks8000 thread on this.
"Sharpness: This applies a sharpening filter to the image to bring out edges in an image. In all modes outside of PC mode, any value above 0 will apply this filter. You will likely start seeing sharpening artifacts if this value is above 20. Recommended values: 0-20 (rtings.com: 0). In PC mode, the recommended value is 50, which is the true image. Higher values will apply a sharpening filter, while lower values will apply a blurring filter."
It's not debatable, yes, you will get no artifacts with "0" but that will be the case all the way up to 20, at "0" you lose image fidelity, you need to test your sharpness with a sharpness test pattern.
None of these sites, ratings, av forums digital foundry apparently feel the need to test sharpening using a actual sharpening test, instead opting for "0" as neutral which has been shown over the years to be incorrect with numerous TV's.