I agree, the IS on my Canon S3 is more effective than what I have on my K20, but not by a lot. But, for posterity, I would much rather have the images from the K20 & in-body IS, than the images from the S3 with its in-lens IS.
No matter how you slice it, the $$ returned on the in-body stabilization system is much greater. And I agree with Vylen's analysis, that holding as steady as possible is better taught with the in-body system.
You can't please all of the people all of the time.
That's a different beast though, because you are using an EVF, so even if the IS was sensor based, it would look the same because you see what the sensor sees, not an optical image. Plus, the refresh rate of the EVF is going to smooth out small movements.