Nvidia drivers use GPL code for their closed driver, this is a GPL violation, and only for this you should avoid nForce, but this isn't all, Nvidia's "way to do the things" is ok for video cards, but is totally incompatible with a motherboard chipset.
Nvdia have to release the specifications as Via or SiS do , or we will never get a decent support for nForce by Open Source drivers (as for Via and SiS and Intel..... and so on) . you will be completely dependent from the binary drivers from Nvidia , and if they have any bugs you have to wait that the Great and Magnifical Nvidia linux support solve it .
With open drivers you have only to post your problem to the linux mailing list and it will be solved in 1 or 2 days (as a problem that I had with DMA on KT400) . And is not all , with Nforce you can only use Nvidia cards on AGP, and great part of the people that I 've heard about Nforce on Linux haven't reported great successfull installations.
All this to say that a Nforce will not work on linux well as any other chipset