Sony Xperia T2 Ultra, HTC Desire 816 or One M7?

Children 6 inch screen and trade descriptions, design of Sony enchanting but the camera looks a little machine.

HTC 816, it has a 5 megapixel front camera, rear camera pretty steady, moderate size machine designed for children but worse than T2.

Whose child is over for some comments on two machines with. My demand is playing the latest games on the market, at least smooth play Low setting.

Although baffling 2 on the machine but is also considering e HTC One M7, designed to look like but unfortunately also find the small screen and ultra-pixel camera hated. Battery life, camera with 2 machines on it?

Kids priority T2 Ultra and 816 (because big screen but like wondering camera and performance) or is despite sacrificing screen to grab One M7?