[riffraff]

how does this compare to having a "to top" button on the bottom of the page which appears when scrolling?

I mean, I understand the difference between showing actual actions or giving more space to content, but I'd like to know of some real studies on it.

[jarin]

It's an extra click

[knewter]

at the bottom...of the infinite scrolling page?

whoosh

[riffraff]

no, at the bottom of the window/viewport when scrolling.