<< will nt work as a good router? >>
Actually, NT4 sucks as a router, IMHO.
NT4 barely qualifies as a router, unless you install M$' standalone Routing and RAS Admin Update (also known as "Steelhead" [somebody, maybe Steve or Bill, has a thing for trout fishing...check out the fly and fisherman desktop wallpapers]), which is not included as part of any Service Pack (I think) and has horrendous consequences when installed in the improper order if your NT box is running certain Service Pack and other server product (Proxy Server sticks in my mind) combinations.
Throughout their TechNet database, M$ has issued numerous bulletins and heavily discouraged the use of multihomed NT4 boxes, especially those running any type of infrastructure service (domain controller, DHCP, DNS, WINS, etc.)
Win2K has vastly improved routing capabilities, but a true hardware router is still tough to beat.