"How much RAM can I install in my laptop?"に関する回答i would recommend to go with 4 GB as recommended from Apple, I installed 8 GB and didn't noticed significant difference
"How much RAM can I install in my laptop?"に関する回答i did the same, i replaced my 2 GB with 8 GB. in Mac, i didn't notice much difference, but in Windows 7 it is so fast.