The Forma is here, and I have a few comments:

• The Forma is about 15 grams lighter than the Paperwhite; wider-but-thinner form factor makes it feel downright wispy.
• The hardware quality isn’t up to Kindle snuff. The sleep/wake power button barely depresses, while the page-turn buttons wiggle in their seats. Not a deal-breaker though. And hey: page-turn buttons.
• The Kobo interface is simple and accessible, but there’s an inexplicable use of italics in the menus that looks terrible.
• The screen auto-brightness adjustment goes through many shades and levels of brightness before settling in one place. It’s not a show-stopper but it feels half-baked.
• Text on screen looks great.
• Calibre works just fine for installing books; you can de-DRM your Amazon purchases and move them over to your new device.

In all, unless you’re married to the Kindle and Amazon’s ecosystem, the Kobo Forma is a great ereader. I’d snap one up, as the Sage is more expensive and has, to my mind, superfluous features if you don’t want to mark up PDFs on your book reader.