>I've yet to see a
>NetBSD system requiring a manual fsck after an unclean shutdown (other than
>because of hardware issues).

Well, I have.  I see about 2 a year on my NetBSD/pc532.  It typically
happens when I'm doing a build and have a power failure.  It happened
a couple of weeks ago on 1.5ALPHA.  It looks like /tmp gets messed up.
I can do a "fsck -y /dev/xxx" and have it back.  Most of the power
fails come back just fine.  Also, I have not lost anything critical in
power fail manual fsck situations.

-- 
Phil Nelson                       NetBSD: http://www.netbsd.org
e-mail: phil@cs.wwu.edu           Coda: http://www.coda.cs.cmu.edu
http://cs.wwu.edu/faculty/nelson