Yes, but using all of them needed for full HTML5 support in, say, IE6, probably takes up more bandwidth than downloading a new browser.

It doesn't take up any more bandwidth if you're properly concatenating your JS.

Uh, no. I think you misunderstand me.

You're right. That was fairly nonsenical. Not sure what I meant, perhaps I read your comment as referring to requests.

Either way, long-term caching of such shims means the bandwidth to load polyfills only has to be expended once per client. And an extra Mb of bandwidth once per year is a pretty reasonable thing to do for particularly older browsers if it makes your development more sane.

Most people using IE6 are doing so because they can't download a new browser e.g. ActiveX support or lockdown corporate machine.