So, I got one of those SanDisk Ultra 200GB microSD cards on sale at Amazon for $60, and having nothing else to do with it I stuck it in my SP4. Figured I'd save a little space on the SSD by setting applications to install to the card. However, now that I've done so, none of the apps that are on the SD card will update. They generate a code in the Windows Store that I forgot to write down, and the only way to get them to update is to move to the SSD. Anybody else seeing this? I have no idea if this is a Windows 10 problem or an SP4 problem, although I tend to think it's the former. If anyone else can confirm that they have apps installed to microSD and that can be successfully updated, then that's a data point for something being wrong with my SP4.