rygD
Nihilistic Mystic
All boards will be identical between all of the units (until/unless they get updated at some point). The differences will be in what is populated (wifi only means no mobile module, if there are 2GB and 4GB ones it is just a difference of how much RAM is present, the proposed non-backlit keyboard version would not have the LEDs around the keyboard and such).One thing that's been bothering me for a while now is I don't know if the non-3G/4G boards will still have the traces for the module but leave that part unpopulated or if that (electrical, not physical) section of the board is gone completely.
I know I won't need the module initially and I'd rather not solder SMD components anyway, but at the same time I want to know if installing a 4G module is possible at all.
As for if you can add 4G yourself later, that depends on skills and equipment, I suppose. It would probably be easier and cheaper for most people to just swap the main board.