In my case (ASUS F555LD and NVidia GeForce 820M, so Fermi series, as FadeMind made me notice) the correct driver was NVidia 390 bumblebee, but the default driver installed was the 440 with prime.
Concerning point 2) on the NVidia website they write there that the 430 driver works fine with the GeForce 820M (https://www.nvidia.it/Download/driverResults.aspx/149323/en). So, since my driver out of the box is the 440 and now I'm running the 390 (not experiencing any problem) I just wanted to point out the possibility that the ID list provided by NVidia could contain errors.
Ok, so maybe the infos on the Nvidia website may not be misleading. However I am seeing now that the 430 comes with bumblebee, so practically there is not so much difference with the 390. As far as I have understood, a significant upgrade in performance comes by using prime or optimus instead of bumblebee. So, for our GPUs basically there's no change