I just order 2 x 8GB sticks of RAM from OWC, and I was wondering if it's ill advised to just add those two sticks to the 2 x 2GB sticks that are stock from the computer? Should I just completely replace the 2 x 2GB sticks, or would adding the 2 x 8GB sticks not really effect performance if I kept the stock RAM installed as well? I know there are weird issues with stock RAM and 3rd party RAM sometime. Normally as long as RAM is installed in pairs, I thought it was okay. Just wondering what some of your experiences were with this?