[texhax] The microtype mystery

[George Gratzer]

My book is 606 pages long. It is a single file plus the .ind file and125 pdf illustrations.

Here are the packages used:

amsmath
amsthm
amsxtra
\RequirePackage[mathscr]{eucal
amssymb
latexsym
amscd
graphicx
color
mdwlist
chngcntr
color
booktabs
url
fixltx2e
verbatim
enumerate
xspace

Typeset time as reported by "time":

real	0m2.595s
user	0m2.527s
sys	0m0.063s

that is, 3 secs. pdf file is 4.4 MB.

Now if I use the microtype package( the book  is now 3 pages shorter):

real	0m35.443s
user	0m35.155s
sys	0m0.115s

typesetting is over 35 secs. pdf file is 4.6 MB.

My iMac has 8GB memory; the whole ms with illustrations is 
tiny in comparison: about 40 MB.

Anything I could do to speed up this typesetting?

GG