sh/Z (was: Poverty)

[mani at srirangam.esd.sgi.com]

No one has still addressed my question of whether using
z/Z for "s is a good trend.  In my opinion, it is very
visually jarring, since it is not intuitive for readers
of English to make a connection between a 'z' sound and
the sibilant is is supposed to represent.  Since digraphs
are still used for 'tha', 'Tha', etc., why not use a 
digraph for one of the sibilants?

Mani