Hello all: I have a new MacBook Air, 1.4 1GHz, Core i5, 4 Gig ram. I wish I had been able to wait and order the 8 Gig model, but I was not able to. I know the ram is soldered to the board, but I am wondering the following: is the logic board manufactured differently for the respective models, or is it that the 4 Gig model has vacant drilled holes and printed leads for the additional 4 Gigs. If this is the case, can I have a technician solder in additional ram, or is the logic board physically different by model? Thanks for your attention.