NVIDIA with Optimus on M6600 .... WTF

I just realized that there's an option on the BIOS of my Dell Precision M6600 laptop called "NVIDA with Optimus".  Out of curiosity, I turned it on, and that caused quite some pain to me, becuase the laptop has bitlocker turned on.  That means every minor change on the BIOS will force me to enter bitlocker passphrase again.  Also I experienced some system lagging and hanging every once in a while, and while I don't know if those were caused by the "NVIDA with Optimus" feature, that was the last thing I changed.  Plus after I turned it off, the lagging problem seems to go away, so yeah, the feature is dead to me now.