Conclusion
I’d recommend installing the 180.48 driver. If you have a large gaming library and/or you play any of the games on nVidia’s list, you’ll almost certainly get a free performance gain somewhere, and that’ll add value to your hardware investment.
Related
IMO, most of the results you found can be discarded as statiscally insignificant. Nvidia’s claims hold some truth, but only under very specific settings and/or resolutions. They brought more then just FPS gains though
True, but to be fair I only tested one game on nVidia’s list (Bioshock), and I observed a good performance gain there with 4xAA.
If you play the games on nVidia’s list, I have no doubt you could see some good performance gains.