]NetBSD uses the BSD NET/2 code, from 4.3 BSD series kernels.
   ]FreeBSD uses the BSD NET/3 code, from 4.4 BSD.

Whoever said that has absolutely no clue what he's talking about.

1) The NetBSD networking code is most certainly based on 4.4BSD-Lite,
with a number of bugs fixed, various 64-bit issues resolved, and more
recent multicast code.

2) There is no such thing as `BSD NET/3'.

   In theory it has the scope
   ]to be faster on PC hardware than the others, but optimisation to really
   ]make it rip is a 1.3.x project

In other words, vapourware.  We don't go around bragging about
vapourware.