I'd be interested in the spec differences, as it just looks reskinned to me.
Even the little box still only has 1 HDMI input.
Main differences are:
Upgraded speakers with an additional driver:
"Each Quad speaker contains four drivers — a tweeter, a midrange, a woofer, and an up-firing height effects unit — for a total of 16 drivers. That’s a step up from the HT-A9’s triple-driver design which was lacking the midrange driver and had 12 drivers."
Better stable wireless connection:
"Radio output power has been enhanced by up to 2.5 times compared to the previous model. Plus, an all-new switchable dual antenna and frequency hopping system ensures more stable communication between control box and wireless speakers."
New calibration:
"Enjoy quality surround sound wherever you're sitting. Just run calibration with our smartphone app, BRAVIA Connect, and BRAVIA Theatre Quad will detect your position in the room and optimise sound to suit."
New app:
The BRAVIA Connect smartphone app guides you through initial settings, assists with troubleshooting, and lets you control volume, sound field and more. It also notifies you about software updates and lets you control a compatible TV too. Don't need remote anymore to adjust volume or the EQ settings. It will also display what codec is playing.