I read the article.

Perhaps I'm misunderstanding, but did they do this test on a 128 kilobit cellular Internet connection?

I made the video in the article using Chrome's "low-end mobile" throttling preset, which simulates a ~300 kbit connection IIRC. But I saw very similar behavior on my actual phone with an actual 128 kilobit connection in Canada.

Thanks for the clarification. Do the conclusions hold up when testing with a broadband network connection?

As I mention in the article, I'm not really able to tell the difference between old MDN and new MDN on the fast network connection I usually use. They both load pretty much instantly for me.

I sometimes wonder if website authors actually test their pages on slow connections before declaring that they’ve improved the experience for them…

Do all MDN users have low-latency, high-bandwidth connections?

I’m a bit lost. How would using a broadband connection affect the relative speed between the two versions ?

For one, latency has a proportionally higher impact on "time to render" at lower connection speeds.

I’m guessing no?