I have Supernote. It has some pretty nifty organization features that the Remarkable doesn’t have- you can create a table of contents as well as tag and star pages. It makes it easier to find the notes you need.
I have been using a small Supernote (A6X) for a long time now and it has become indispensable.
The hardware is good, the writing experience is excellent, a good calendar application, the battery lasts a long time, etc...
But all those are not the coolest thing. The coolest thing is that the guys who write the software actually listen to their customers and implement features and optimisations regularly.
I do embedded device software for a living and I know that the most expensive, recurring part of development for a gadget is the software updates and support long-term, where "long-term" means more than a few years.
Not many companies will support the same hardware device with fresh updates (and new features) regularly over a long(ish) period of time, and that is what Supernote does, and that is why I like their product.
Apple is rather good at this; companies with Android devices, not so much.
Reading myself I realize I sound like a Supernote fanboy... actually I am a big fan of maintained software, and that is a rarity nowadays.
Of course, when your device is _liberated_ and runs open-source software, you can finally hope for actual good software support for more than a couple of years ... but that is a topic for another time.