Hacker News Reader

526 on Chrome 61.0.3163.91

478 on Firefox 55.0.3

and here's the kicker, tested on an ancient pc from 2004 with Pentium 4

Parent does say "The latest tech preview", notice?

Parent does say "the last released version," notice?

That's for 10.2 (the next release version, which is not, er, released yet) as opposed to the Tech Preview. They list it here:

same here