Sadly, they are problems with the microSD card on the Surface Pro 2. For some reason, the CPU is under used by about 30% all the time when the microSD card is in. I don't have such card to confirm this report, but it seams like many have the problem.If I don't expect to need more than 128 GB, do you think it's wise to buy a unit with only 64 GB and then add a 64 GB micro-card, thus saving substantial money over purchasing a 128 model? Would there be a downside?
Just to be safe, I would not trust it, and just use it to transfer stuff in and out of the Surface Pro 2 instead for a moment.
While I am sure that Microsoft will fix this issue. No one knows when. So it's going to be risky. I think spending the 100$ more for the 128GB is worth it. And will boost the resale value, I think, of the device.
Look at prices of SSD's, even IF you COULD upgrade the SSD, it would still be cheaper to get the 128GB in the first place built-in.