Not so well. I don't think the problem is in the composing of blog posts but in the reading of them via IE 6.0.
Trying to center type or do block quotes in the "compose" mode is an exercise in frustration, and photos that appear at the top of a post often obscure the headline below. It might look OK to users of other browsers, but it looks like hell on IE 6.0.
And type is occasionally not appearing but does show up when you screw with the window a bit.
NONE of these problems happen on the Mac with Safari (which doesn't support full Blogger functionality). Guess I'll have to go back to Firefox, even though the Blogger help pages insist that IE 6.0 works just fine (although the Blogger people all use Firefox, so you know which browser gets all the love).
Maybe I'm missing an IE update.