Notebooks that use NVIDIA Optimus messes with the Rift. This Asus ROG G751JY does not have Optimus, which is good.
http://rog.asus.com/forum/showthread.php?52651-G751JY-Does-Not-Have-Optimus
This thread goes into more detail, though not from the Rift’s perspective, you can find a few here on the UE4 forums.