The real changes come in the full HD 5.2-inch display, which offers brighter colours thanks to Live Colour LED technology, clearer sound quality through Sony’s Front Surround, and a 20.7-megapixel camera capable of shooting video in 4K.
The Z2 uses the Android 4.4 KitKat operating system and is powered by a 2.3GHz quad-core processor, with 3GB of RAM, a 3,200mAh battery.
Because of the Snapdragon 801 processor, the Z2 should run faster than its predecessor but internal storage remains the same at 16GB.
Sony's Z2 Android KitKat-based, 10.1-inch screen Z2 tablet also runs the 801 and is 0.5mm slimmer than its predecessor at 6.4mm.
Ovum senior analyst Nick Dillon said the Xperia Z2s are modest updates to Sony’s flagship smartphone and tablet devices.
"But their importance in helping to re-establish Sony's brand and design credentials should not be discounted," Dillon said.
"Design refinements, improved screens, and 4K video capture are clearly incremental improvements."
Dillon said the flagship devices embody the One Sony philosophy set out by president and CEO Kazuo Hirai two years ago, combining technology from Sony's TV, audio, camera, and gaming divisions and content from its media business.