Thank you for feedback! This is exactly how browsers render SVG filters currently, and it looks the same edgy on my non-retina Mac too... And that's why I've

Thank you for feedback! This is exactly how browsers render SVG filters currently, and it looks the same edgy on my non-retina Mac too... And that's why I've included a separate script (make-screenshot) which uses PhantomJS and ImageMagic to render high-quality hi-res version of your wireframe. I used that to produce screenshots for github readme. Another option is to try zooming-in a bit in browser, like to 125%, this way it looks a little bit better imho.