[joaobeno]

This is just another attack on the open & free internet. Why so? Since Google defines per their own metrics fast vs slow, they will imprint that impression upon the user, making an otherwise good willed user a starting bad impression on your site.

As people pointed out, this will make AMP even more attractive, driving more traffic away to Google...

Also, it may impact sites hosted on cheap far datacenters, like my user being in Brazil, and my server being in Virginia. Suddenly, my site is considered slow by Chrome, while my rich competitor who hosts in São Paulo gets the "fast" badge...

I think this kind of classification creates extra confusion and impact at no tangible benefit to everyone that isn't Google.