Lex,

> This case happens a LOT for formatting HTML.  Every link,
> bold, italics, indentation, and font-size change all start a new set
> of text attributes.

True, but usually they stay constant for quite a bit. In your example, we
have 5k text with 212 different runs which makes for an average of 26
characters per run. This should actually be enough to show some improvement.

> What can I say?  Your download didn't fail, did it, leaving you
> formatting an empty page?

It didn't. But my timings still differ. What hardware/OS did you run this
on?! Did you try it with the latest changes to AttributedTextStream as
well?!

[BTW, the reason I'm interested here is that it seems this might be a
machine difference; I am wondering what kind of effect could cause this
behavior. Considering that most of the execution time here relies on mcache
and atcache behavior it could be very helpful to find out]

Cheers,
  - Andreas