http://blog.gsmarena.com/sony-xperia...e-the-results/
You just can’t rely on the Z Ultra for web browsing on the go (especially if you use LTE instead of Wi-Fi). You’ll be able to squeeze in a couple of movies before the battery gets too low for comfort, but the Sony Xperia Z Ultra just isn’t the ideal tool for road warriors that it could have been. It fares much better at home where you can plug it in when the battery drops or just use it as a secondary device that isn’t mission critical.
And Sony continues to fail...