The Spring Design Alex, the other dual-screen Android ereader, is what I had hoped the Nook would be: an ereader for hardware nerds.
The hardware is thin to the point that you worry it might snap - a common thread in ereader design, actually - but it feels about as sturdy as a Kindle. The screen is standard matte e-ink, which did a good enough job at blotting out the harsh lighting in the conference centre. The bottom screen is a bit taller than the Nook's, giving the whole device a gangly look. But it's not the screens that matter, it's what's on them:
That is to say, whatever you want. The Nook's screens are like content ghettos, with the top intended just for ebooks, and the bottom for navigation. On the Alex, there's effectively no barrier. Ebook navigation is similar to the Nook's, with the faster bottom screen serving as a touch interface for the top, non-touch screen, but it'll also run any Android app, stock or otherwise, including the browser, email client and music player apps. Best of all, you can push content from the bottom screen to the top whenever you want, meaning that you can navigate to a web page on the bottom screen, then once it's rendered, send it to the top.
There's a steep learning curve and it doesn't feel like the interaction between the two screens is fully worked out, but it's no less awkward then the Nook, and capable of a lot more. I wouldn't call it the Nook on steroids, because in some ways, the Nook feels disabled. So, I guess it's like the Nook, except without two shattered kneecaps? That'll work.
The only hitch: It might be tough to convince a wireless provider to agree to unlimited, free, no-contract data like the Nook's or Kindle's, because this thing is primed to use a lot of bandwidth. Not coincidentally, you can't buy this thing yet. That said, an official announcement of some sort is due this Thursday, so don't give up hope.