Took the time to make such a comparison using the article's sample images (even if the filter isn't sharpened in those), same thrice doubling of the small picture: http://0x0.st/XEEZ.png
I find such a test strange and irrelevant, though.
Ooh the animated comparison is really helpful. I couldn’t see it in the article, but with your version the Magic version feels flatter, almost like it’s a bokeh blur and not just a low pass. The Sigmoid seems far better than either Magic or Bicubic.
I find such a test strange and irrelevant, though.