[Xperia Z2 Q&A, Help & Troubleshooting] xarfrost:
Why I like the Xperia Z2 over other competitors (Galaxy S5, One M8, G3). Below are just my personal opinion and observations. I have used my Z2 for 3 weeks now. This is my first noob review so please bear with me.

Camera

I was disappointed when I first heard that Sony limited its Superior Auto mode to 8MP only, I admit Im one of the people who believes more megapixel the better, but I was wrong. Even at 8MP, Z2 captures amazing shots, HDR is not as great as Galaxy S5s HDR shots, but as a whole camera, its better. Color accuracy is near perfect as I have compared through reviews. 4K video, although it heats up the phone quickly, I dont often use them. 1080p video recording is great, with a choice of 30fps or 60fps, sound is loud. Shots are fast and focus is 90% hit. Dont mind about HTC One M8's "Ultrapixel", they shoot awful shots.

Battery

3200mah Z2 vs 3200mah G3? G3 with QHD screen undoubtly will eat up more battery that Z2's FHD screen. Galaxy S5's 2800mAh and HTC One 2600 will normally never last longer than Z2. Rocking the phone for 24 hrs is a piece of cake. Dont forget Sony's Stamina mode that saves up a significant amount of juice.

Screen display

Although many people have been complaining about Z2's screen a bit dim. In my opinion its not too dim or too bright that I have to squint to see what im looking at. In my observation, Z2's brightness bursts from 75% and above. Previous flagships use TFT LCD and that was a big deal breaker for me. I could have got the Z1 if the screen was IPS. Texts and icons are sharper and brighter. Images are more vivid and accurate. Coming from Galaxy S4, I am used to those AMOLED displays, downside is that its not as sharp as IPS LCD, plus X-Reality does the job well done to movies and pictures (sharper and more vivid). As for HTC One M8, screen is comparable to IPS, but gives a bluish tint as I have read. Imagine yellows with blueish/colder colors.

Stereo Speakers/Sound

HTC is undoubtly the champ. But we are pinning Z2's dual front facing stereo speakers at 2nd, ahead of Galaxy S5 or G3 with one speaker. Sound is a bit soft/low even at 50%. You wont even notice a significant change from 1%-50% volume. Volume bursts from 50% and above. Thats just my opinion. Theres a little bit of trick with Z2's speakers to sound great or at least better. Watching movies or listening to music in landscape greatly improves the audio experience. Its probably because sound is distributed well to your left and right ear.

Noise-cancelling headphones

Its my first ever high-end earphones ever had. I was amazed how it cancels out 98% of background noise. And its 0 outside noise when im playing music. I couldnt even hear my friend shout at me. Bass is good, im not a boomboom person but I think its better than my GS4 generic headphones, or my Sony MDR ZX100. Definitely a steal.

Design/Build Quality

Coming from GS4, im loving my premium Z2. The glass and metal finish it has over Samsung's plastic, and horrible GS5 design, GS3 was good though. M8s design is good too, but that camera and battery :(. G3 is a bit big for me, and the back buttons are something that needs to get used to. Although heavy (Z2), Im getting used to it. Im using Spigen Ultra Fit case for increased grip and protection. I believe its a must for cases because the sides of the Z2 is kinda slippery. And I dont wanna scratch the back glass, lol.

User Interface and features

I find Z2 a wee bit lacking of features, like Touchwiz S-Beam. Palm tap to mute, especially calls and alarm and Smart Stay. Nevermind smart scroll and Air view stuff, they are hardly useful. The Sony UI feels light, not much bloated than Samsung. And it doesnt lag!! Unlike Samsung. Generally speaking. The UI is simple and snappy, though personally I feel its getting old/outdated. Needs to freshen up the icons and apps. With the new Quick Settings tab under notification, its a big improvement from older android versions with only limited and un-editable quick settings

Conclusion:

Coming from Galaxy S4, I am not disappointed that I ditched GS4 for Xperia Z2. With the screen improved from TFT LCD to IPS LCD, with 2 front facing stereo speakers, with the much improved camera than the previous Z1, the premium noise cancelling earphones, a premium phone made with glass and aluminum, water-proof, and ofcourse the massive 3200mAh battery. You cant go wrong buying the Xperia Z2.

Upon writing this lousy review back from a fresh shower, I just dropped my Z2 (with case ofcourse, 2nd time) from shoulder height to the floor tiles, and survived. Not a single scratch or crack.