I have a Toshiba laptop with hybrid graphics Nvidia GT 745m and Intel.
I have it all working with the recommended nvidia-331 driver.
All is good except for random freezes. It only seems to be the graphics that freeze as I can still ctrl-alt-f1 and alt-f7 to fix it.
I can solve it by switching to the Intel graphics in the nvidia settings, but then I can't do anything with decent graphics.
The second issue is that I can't use HDMI with the nvidia GPU active. It just crashes to log on.

Im having these issues on both Ubuntu 14.04 and eOS Freya beta 1