I have a Supernote which I like primarily because it's repairable and the developers are very responsive. It's the A5 version. It's very nice to write on and if you haven't tried eink in a while, it's pretty impressive. The soft surface is also a replaceable film. It has a Lamy colab pen which is very nice.

Downside is no backlight which many users tout as an improvement, or praise it as a minimalist perk. I don't really agree, but it does mean that the ink surface is closer to the pen so there's less parallax error. It makes it less usable as an ebook reader though, for example on a flight you'd have to use the blinding overhead lights.

Sure the price is comparable to 20+ notebooks. I think if you actually use notebooks, they're good. If you don't, it's questionable whether it'll change your habit. It also doesn't replace the satisfaction of a nice ink pen on nice paper. I have a collection of fountain pen ink that I've used since university (for years of daily lecture notes which is more writing than I'm ever likely to do again - we're talking up to 20 A4 sides a day) and the bottles are still practically full. So good writing equipment can be very economical. There are other issues like no colour (on mine) and PDF support is still ropey.