Seems like the base model is the 64 gb eMMC BUT if it is going to be the same exact board as the NVMe model than most likely people will be able to upgrade their own systems. Meaning, you can just populate your own board with a NVMe of your own choosing. It also seems highly customizable OS wise and is basically just a handheld computer which is able to run win10 which suggests that steam isn't going to be locking it down in an attempt to prevent users from upgrading their own systems. However, the ease of repair on these devices will need to be known though before that could be attempted. Depending on how it's designed it might be incredibly easy to get into OR it might be designed in a way that makes it as hard as possible to get in i/e everything's glued down rather than screwed down.