The main issue I had with my Remarkable 1 was that I couldn't quickly scroll through pages of e-books. If I was looking for something specific in the pages, an ipad allows me to swipe across rapidly. Remarkable was this tedious repeated button press, waiting each time for the screen to refresh. Had to go back to ipad although I loved the device.
Kobo lets you tap and hold a corner (or hold down the page turn button), and after a second it'll start fast-flipping through pages. Not as fast as an iPad but pretty quick, sorta like flipping through a book at a moderate pace.
Onyx BOOX. Set the refresh rate to anything faster than "Normal"/"Regal", and you can page through docs pretty much as fast as you'd care to.
NeoReader (Onyx's book reader app) also has a lightbox / page preview mode where you can see 4, 9, or 16 pages at once. Obviously too small to read at 16 pages up, but good enough to spot figures, diagrams, chapter breaks, and the like. That renders pretty quickly on ePub or generated PDFs, but can be slow on scanned-in books where you're looking at images of text rather than rendered text.
Both Kobo and Kindle devices allow you to fast scroll page thumbnails, which helps work around the refresh limitations of e-ink. Something like that is still missing from RM's software. You basically have to switch to multi-page view and then scroll that if you want to go quickly through a document.
