So.....I discovered something new in a bad way. SD cards only go in half way. Each time you work, you have to replace that SD card. My idea of waiting for the 2TB SD cards for storage extension in the surface book is a failed idea. I only have a 512gig ssd so this thing is going to fill up a lot if I put it all on the main drive. Now I'm going to constantly attach a hard drive to it when I do my work. Do you guys have another solution to this? This is very strange to me and of an issue.