當然，有人有異議：

http://home.no.net/toeng/justering/gut_hz/gutenberg_hz_english.html

- the article made objections to some of the points claimed
by URW, Hermann Zapf and others. I more or less agree with
the objections in the article.
- however I do not agree with main intention of the article, ie
to show/prove that glyph scaling leads to reduced quality.
The objections in the article are not convining enough to
me. It only showed that there are some inaccuracies in
what URW/Zapf/Adobe claims. Given the fact that those
claims are made by the authors of the technique, it's
quite normal that the effect/usefulness has been
exaggerated a little bit.
- glyph scaling is only one of the techniques used by
Gutenberg and the hz-program; it's not meant to be the
single silver-bullet that would solve the problem with bad
interword spacing. The hz-program does much more than just
glyph scaling.
- like other techniques, glyph scaling is also a double
edged sword: it can help and also hurt. The users should
be aware of that.
- I use glyph scaling myself and find it useful, especially
when you want to give a bit more flexibility to paragraph
formatting and there is no other possibilities to do so.
The limit I find useful is +/- 2%, but when looking
closely I can also see the effect of glyph scaling at that
limit. I guess -1% to +2% is a better choice.