It also puts every single special character into its own span. That may negatively affect programs that trust HTML for copy-paste, for example Open Office, Microsoft Word (I think?), some IM clients, some text editors, etc. Doesn't seem worth it in the general case.

That said, if those sorts of things bother an individual, they could run that on the page themselves, I suppose, so it's good for that :)

I don't know OpenOffice but In most programs putting spans around a letter or word does not affect pasting.

10ms is a huge amount to spend for such an obscure fix. How many obscure corner cases do you think Google webpages have to account for? A lot more than 100, I would bet. So rough methods like these would be horrible for performance.

I invite you to look at the ridiculous amounts of JS lines twitter uses in its interface.

You're the one who made the 10ms claim, not me. If indeed it is faster than you claimed, then maybe it would be ok. Still probably not worth engineering time for a problem of this magnitude.

And Twitter is horridly slow on its website. That's what we're trying to avoid