Fill the special box with relevant results to the search, and use load time for the result as a weighting. So if your content is ridiculously on-topic but a little slower to load, you'll still probably be in the special little box, but a slightly less specific site thats super fast to load might be before your site.

As has been mentioned: google has used page load times as a metric for a long time. The difference is they didn't add a "special little box" to incentivise sites with otherwise shit decision making skills to do the right thing.

But sure. Tell me how forcing clients to download a bunch of javascript, and introducing forced 8 second blank pages for anyone who dares to not load said javascript is all about making pages faster.

Give me a fucking break. If you want to live in the fucking google sphere, that's your choice, but don't pretend that their motives are anything but hostile to the very concept of the open web.