I have as well, plus the devices do some sketchy phoning home to servers in China. Unfortunately, their hardware does seem to be better than the other choices, at least among current models.
(edit: I should add that lately I’ve only been looking at 10" screen models.)
The Boox, Supernote and ReMarkable brands are a few of the typical choices.
I’ve heard Onyx (Boox) uses Linux but doesn’t release source code, for people that care about GPL violations.
I have as well, plus the devices do some sketchy phoning home to servers in China. Unfortunately, their hardware does seem to be better than the other choices, at least among current models.
(edit: I should add that lately I’ve only been looking at 10" screen models.)