Can I suggest changing the CSS units for fonts from points to pixels? That way HN will look the same on both Chrome and Firefox for me :)
On Chrome 10pt HN type is 12px on Firefox it's 13.3333px (Mac OS X).
(Apologies if this is not the way to do this! Thank you for HN!)
And what does it matter if it doesn't look the same on every browser? It definitely doesn't change the experience.