I'm going to be buying a new Macbook Pro in the coming week, and I was asking him about upgrading to 4GB or RAM........He stated that it is better just to go with the 2GB of RAM that the MBP is shipped out with, and THEN at a later date IF I needed the extra RAM, that I could take out the existing RAM and install 2 2GB of RAM...... Which is better?: 1. To immediately upgrade to 4GB of RAM? 2. To use the MBP's RAM that it comes with....and then at a later date (months/years later), to upgrade to 4GB of RAM at that time?