routing and remote access is basically the same as a hardware router.  You'll be able to do NAT vs ICS and have many more options for configuring your network.  The drawback to NAT on win2k server, is that port forwarding is very limited in that you can only forward single ports rather than a range.  Thus if you want to forward 20 ports, you'd have to make 20 entries rather than entering a range. 
With the price of SOHO routers being so cheap, I would just pick up a netgear or linksys router rahter than using win2ksrv to do NAT or use linus to do ipmasquerading, which is much more flexible using config files that win2k is.
I used to do NAT with win2k server on one of my spare boxes and got fed up with the fact that it was a severe pain in the ass to configure ports to allow for hosting games etc...so I picked up the netgear rt311 for 50 bux from best buy and never looked back.