Looks neat, but not being able to do something as simple as backup and sync without a monthly subscription makes this whole ecosystem a no go for me. Especially for a device that already costs $600-800.
This is my stance. I'm increasingly just not buying anything that isn't have FOSS. Artificial constraints that try to force a subscription are a hard no.
You can break the custom integrations that they created or even brick the whole device.
But nothing is stopping you from logging into the system and modifying anything you want. There's actually a whole ecosystem of 3rd party mods and software for the ReMarkable!