[Quoth]

I got a second hand reMarkable as well as a new Elipsa.
1) reMarkable has no onboard handwriting recognition/conversion, uses "cloud service", which now needs a subscription!
2) reMarkable does epub by converting to PDF!
3) reMarkable 2 weighs more, replaces matte plastic front that's not too slippy with glass front harder to write on and has no page or home buttons. Slight CPU upgrade.
4) Both reMarkable models have only 6 G byte flash for PDFs!
5) Elipsa reading is the same as any Kobo and simple KOReader install for auto-crop PDFs. The reMarkable PDF viewer does crop, but you need complex install of KOReader for epubs.
6) No mass storage or MTP mode on reMarkable, uses USB network and browser or an application for some OSes.
7) The Sony 10" & 13" Digital paper are really virtual PDF printers and useless without the host program (only some OSes).
8) The Elipsa screen looks better
9) Kobo bought in Nebo, one of the top handwriting, shape and maths conversion tools. It's also on Mac, Windows, iOS/iPadOS and Android if you have a digitiser and active stylus. The nebo files can be used on the other platforms and it exports docx, text and HTML. The basic notebooks are images and export PDF or PNG etc.
10) No host app/program is needed with the Elipsa. USB mass storage and simple copy of exported files. 100% Calibre support for epub , PDF, series, collections, covers and copy back text annotations.
11) With 32 Gbyte Flash (most of it free) the Elipsa hardly needs SD card. No SD card on reMarkable.
12) Elipsa and Sage use the same design of pen/stylus as the MS surface (version without OneNote BT is fine). The reMarkable allegedly uses a custom Wacom EMR (not same as standard Wacom pen) pen; advantage is no battery, but disadvantage is ALL Wacom pens are powered from the digitiser system, a big increase in tablet/ereader consumption compared with 6 months for 30c AAAA cell or about a month for rechargeable pens/stylus/pencil.

Be suspicious of ANY product that needs a cloud service or host program/app for any functionality. Avoid anything that does use USB mass Storage or USB-MTP.

The Huawei 10.3" eInk MatePad Paper would need to be at least as good or better than the Elipsa.

Does it decently convert handwriting as well as Nebo?
What 3rd party pen/stylus works?
How is stuff exported?
Will it be 100% functional without WiFi or Internet?

A second-hand reMarkable is only OK if cheap and wanted for PDF novels.



EDIT:
Previously I incorrectly claimed: Elipsa is a real 300 dpi, the others are lower resolution. All the 10.3" are 226 dpi?