What applications are you going to be using?
Overall, the V5 svcks bad for modeling, but for certain applications it actually is quite comparable to the GF2(those that don't use hardware T&L, aren't very picky about drivers etc).
If you are talking Maya or SoftImage, forget the V5, right now, forget it
If you are looking at Bryce, Poser or some other entry level package then the V5 doesn't do to badly. Even if you move up a few steps in the viz ladder as long as the application doesn't choke on 3dfx's drivers and you are using very low levels of geometry then the V5 may be tollerable.
For certain applications(Maya, S|I), I would take a TNT 1(yes, I mean a TNT1) in a heartbeat over a Voodoo5 and no, that isn't a joke.