I mentioned to someone that I was thinking of buying the optional 128 or 256SSD on the MBP I intend to buy, and perhaps in a couple of years buying an SSD of greater capacity. (The 512 is beyond my budget at present.) The person I spoke to didn't think this was a good idea because the 128 and even the 256 would soon fill up with photos, and that I would then want a larger drive. (Backing up an external drive is of course highly recommended, but it's pretty neat to have all one's photo collection on the computer's own drive.) Replacing an SSD with another, he said, was a "dickens of a job" as the existing (factory) SSD is built into the mother board. What's the scoop on replacing SSDs... easy, tough, impossible?