I have a 2009 MP flashed to 5,1 running a Zotac GTX 750ti with the web drivers. Recently I found locally a Mac edition GeForce GTX 680. Its at a reasonable price but I am unsure if it's worth the upgrade. I still have the GT 120 in my Mac so if need be for a boot screen I can use that card. Do I keep the 750 or change for the 680.