PoC: Reading minutes are a better metric for progress than a scrollbar

I am experimenting with "reading minutes left" as a better indicator of progress on a page. This is similar to what medium.com is doing for their articles, but it could be extended to any web page.

The extension does not work everywhere, but it works on wikipedia and articles from theatlantic.com if you want to try it out.

What do you think? Is this useful to you?