I'm trying to understand the differences between graphics cards that share memory and graphics cards with their own dedicated memory. The only reason I have been considering the 2.2, 15" MBP is its 1GB dedicated graphics memory option. Size-wise, I prefer the 13" MBP, but its graphics card is a turn off. I notice that Apple's website states "384MB of DDR3 SDRAM shared with main memory" when describing the 13" MBP's graphics capabilities. Can the graphics card in the 13" MBP use more than 384MB? If so, how much more?