Using my 1st Nforce board, no problems here I am quite pleased with it, always had via chipset boards in the past.
I am looking at the - Abit AT8 32X - ATI® RD580 Crossfire when its finally released as I will eventually be crossfiring probally, I was interested in the Asus one but put off by all the hassles etc that some people are still having & quite shocked they released it early with all the faults expecting the customer's to be the beta testers for the board - disgusted, a motherboard should work out the box regardless of how new it is.
If your going to run 1 graphics card only, then I would go with the Nforce 4 as you will probally find its more established, had quite a few driver updates etc.