SA-scan compared to exiscan

Hi.

I've been using sa-exim on a customers site for a month or two now and
it works flawlessly. Excellent work!

The customer now wants virusscanning as well, and I looked into
the exiscan-patch (http://duncanthrax.net/exiscan/), installed it on
another customers site who wanted only virusscannning.

To me, sa-exim and exiscan seems to be doing the same thing,
except exiscan also does virusscanning, and sa-exim has more fancy
smtp-reject options like teergrube'ing.....

Could someone please tell me more about the difference between them?

-- 
Audun
http://audun.ytterdal.net