The Keystone has an interesting history. It used to be the Cobo Vault, and Cobo abandoned it, leaving all the users with a quickly deprecating device that is near-useless with modern wallets. Keystone picked it up and ran with it, and to their credit have been maintaining the firmware. My biggest gripe is that the interface becomes very unintuitive once you stray from the "happy path" of native segwit. Also the device's battery doesn't last very long.