The Onyx Boox Note Air 2 looks and feels like the offspring of the Apple iPad and an Amazon Kindle. With a 10-inch display and note-taking abilities, it’s a tablet, yet its E Ink panel means it’s eyestrain-free. But unlike an iPad, it can run for weeks instead of hours. Unfortunately, its slow-drawing E Ink panel has a few quirks. So should you buy one for around $480?