Relative merits of different approaches (ipf, ipfw, ipnat, natd, etc)

[John]

I have looked at the FAQ, the handbook, The Complete FreeBSD, and haven't
found anything like what I'm looking for.

There seems to be 2-3 implementations of access control lists and
2-3 implementations of network address translation that apply to
FreeBSD.

Is there anywhere that discusses the relative strengths and weaknesses
of these different implementations, and why you might want to use
one rather than another?
-- 

John Lind
john at starfire.MN.ORG