Books

How does it fare with standard Android or web apps, email, transitions etc.?

Pretty well. It comes with the color correction set to "grayscale" by default, so that helps. Most apps work fine, but a few have color/theme choices that make the text look washed out. Usually that can be fixed by adjusting theme settings. It also comes with animations disabled by default. When one does slip through (like if it's built into the app), it's usually masked by the slow-ish e-paper refresh and only slightly noticeable.

How large is it?

The photo in my post makes it look a bit bigger than it actually is, but it's a bit shorter and a bit wider than an average smartphone. The screen is 4.3" with a 4:3 aspect ratio so it's a bit wider than I'm used to (which I love since horizontal pixels have been stolen from us on mobile lol). The smaller screen is mostly made up for by not having an on-screen keyboard take up 1/3 of it. Approx dimensions (with case) are a bit under 6 inches tall, 3.5 inches wide, and 1/4 inch thick.

is Battery life better than on a normal smartphone?

Depends how you use it. Its battery is small for a smartphone (3000 mAh), but the eink display makes up for that. I can get a full day of heavy use out of it, plus plenty to spare. The less the screen has to refresh / change, the longer the battery lasts.

BTW there are other good minimal launchers for Android

I switched to NeatLauncher on this one. It's like the stock Minimal Launcher but better in every way.

PS: do get the case asap

I 3D printed one last week. Still waiting on the screen protectors to get here, but this homemade case seems like it'll do about as well as the OEM one.