Well, I just got a new laptop for playing games (I know PCs are better, you need not to tell me), and it worked alright for some games, but for others it used the Intel Graphics 4000 for processing as opposed to the dedicated GTX 660m. It only happened for one game that I tested (Just Cause 2 @ 4 fps high settings) but after a recent driver update (310.90 Beta) it all uses the Intel. Even after trying to 'bypass' Optimus with the 'Select preferred graphics processor' pull-down menu with the Intel 4000 and the GTX 660m, it STILL uses the Intel. Ugh, what a waste of -850.
Specs (In case you are curious):
Lenovo Y580
GTX 660m / Intel 4000
1080p, 60hertz screen
8 GB of RAM @ 1600 310.90 Beta (Most Recent)
-Thank you for your time
1 TB, 5400 rpm HDD(no 7200 available)
Driver Version