[Crowriver]

I haven't tried the Note Air but I do own a couple of earlier model Boox tablets, a reMarkable and a handful of Kobo e-readers.

I don't really think these devices are directly comparable. Boox runs on Android, which gives more flexibility and customisation options but also much more complexity. reMarkable is a more minimalist platform, but offers the best writing experience. The subscription may be off-putting for some new buyers, but doesn't really affect core functionality. Kobo excels as a reader primarily, I haven't tried the new note-taking devices but it seems the software is not yet as mature as the other two platforms. If Kobo fix some of the issues then devices like the Elipsa could really be a serious option.

reMarkable and Kobo in their stock configurations are simpler and easier to use than Boox, albeit less customisable using the standard firmware. Both platforms are based on Linux which makes them hackable, as we all know from reading the forums here and elsewhere. This is an unofficial strength, in that it allows for third party software and scripts to customise these devices and unlock potential uses not supported by the manufacturers.

So which device or platform you choose depends on what use you have in mind for it. Currently Boox platform is the best "all-rounder" out of the box. reMarkable is best as a dedicated note-taker but still not great as a reader, and I would say Kobo is best as a dedicated reader and not (yet) a brilliant note taker. But it's possible to hack reMarkable and Kobo devices to gain extra functionality.

Ultimately it's all a bit more complicated than saying "this is the one device you should buy". They're all somewhat different, and each has strengths and weaknesses.