FreeBSD 4.11 has great forwarding performance when compared to  
FreeBSD 6.x and OpenBSD in general. For a VPN project on WRAP, I had  
again a look at OpenBSD and got a little surprise:

OpenBSD-current (soon 4.1) is catching up with FreeBSD 6.2:

Test setup: Notebook - LAN.WRAP.WAN - Notebook

WRAP device performs DHCP and NAT service to clients on LAN side,  
while using DHCP on WAN (basically m0n0wall's default setup). 'iperf - 
s' is running on the WAN side Notebook and 'iperf -c -t 60 -i 10' on  
client. This sends traffic from LAN to WAN.

m0n0wall 1.23b4: 33.2 Mbps
m0n0wall 1.3b:   27.8 Mbps
OpenBSD 4.0: 	 16.3 Mbps
OpenBSD current: 27.2 Mbps (March 3rd snapshot)

Still not as good as m0n0wall based on FreeBSD 4.11, but its getting  
close for me to be considered again.

Marcel