Regardless of what Chromebook you buy, before you buy it you should find out the device's Auto Update Expiration date, or AUE. Currently, non-Google hardware is only supported for so long before it stops receiving Chrome OS and browser updates, including those for security. For models released now, the date is roughly seven to eight years from the initial release of the device, but that's not always the case. Google maintains a list of AUE dates for all models and you should check it before you buy a Chromebook, new or used.