I think the remarkable is better because it's not a full tablet.
It's an incredibly good scratchpad and is fine for reading papers. The epub reflow and layout is incredibly slow though, and PDFs suck because you can't resize them.
If I didn't have kids/made more money I'd probably buy the Pro but that's not my life now.
I have a boox note air, and if you use it as a "full tablet" then you're doing it wrong and will not enjoy it. It shines as an ebook reader (it runs kindle and kobo as well as epub readers and calibre companion). I run file sync on it so it always matches my library. I take notes (using the remarkable pen which is better than the boox note one and works great with it). But I don't use it for browsing or anything like that, the slow screen refresh just makes that sort of thing miserable.
How hacker-friendly is the Note Air? Is it heavily locked-down or is it more on the open side?