I had asked this question in another thread before so please don't flame me for being redundant, I'm really just trying to get some straight answers and solicit opinions from people. Anyway, I heard and read the the DDR2 RAM used in the MBP works best when installed in pairs to get the full 128 bit access, so if I opt for the 3gb RAM option, will I lose that benefit? I spoke to an Apple sales rep about this and he put me on hold to check with a tech support. He came back with some vague answer saying that I won't lose the benefit. "Benefit of what?" I tried to press him to answer my question but I got the sense that he really didn't know what he was talking about. So does anyone here have a definitive answer? If this is indeed the case, isn't that poor engineering decision to allow only up to 3 gb of RAM? I guess unless you can install 2x1.5bg. Will going for 3gb of RAM still a wiser choice even though you wipe out the benefit of 128 bit access? Thanks in advance for any comments.