[28inch]

"It’s beautifully legible" I couldn`t disagree more. The body text set with opensans on Windows(especially in chrome) looks awful.

[huhtenberg]

Care to show a screen grab?

There must be something off with your setup, because OpenSans is very legible, even on Windows.

[camus]

I agree , sans serif is just not readable. A mix between serif for text and sans ( for headers , titles ,etc ... ) is the way to go. I just cant read any long text that is sans. It's very painfull.