If you’re willing to upgrade the SSD, the case and the screen, I don’t think it makes sense to choose the SD, but that’s one of the advantages of it - talk about hardware of software, it’s pretty much as open. The main advantage that remains is arguably Steam OS, but even then is it impossible to run it on an Ally?

If you’re willing to pay that price, you may as well buy a ROG Ally, but as far as I’m concerned, I’m very happy with the SD as it is.