Hello fellow Macrumors addicts. I will be upgrading and getting a 17 inch Macbook Pro (late 2011) in a few days. I recently became aware of this thing called "optidrive". Im really interested in running OSX and a few essential Applications off of the SSD and having all my multimedia files on the HD. So my question is: Would it be better (overall) to get the 750 GB HD that comes with the Macbook Pro and then move the OS to the Optidrive SSD----Or should I pay the extra $100 to get the 128 GB SD pre- installed with the computer and add in the HD? Thanks!!!