lucy24 - 1:04 pm on Nov 12, 2012 (gmt 0)
If you try both ways with a long chunk of text, you can see where the difference happens. Watch for the point when page loading seems to freeze. I think technically innerHTML takes longer, but it happens later so it doesn't interfere as much.
And of course document.write is risky because if there's a glitch and it doesn't write while the doc is still loading, then your whole document will disappear :) Better to save it for things like popups that don't have any other text to collide with.
* For, ahem, a given definition of "need".