Amazon’s newest tablet, the Kindle Fire HDX, is a good color tablet with a few improvements, but isn’t as versatile as its current rivals, suggests Walt Mossberg. Its best feature could be the video chat-based tech support, activated by its Mayday button. The latest 7-inch screen version starts at $229. Mossberg describes the tablet as a “hardware gateway to buying digital content from Amazon.” The basic model includes ads, but a version without ads can be purchased for an additional $15. Continue reading Tablet Review: Amazon Launches Kindle Fire HDX this Week