Sony Xperia Z2 vs Sony Xperia Z1
We can call these two the “average performers,” as neither their earpieces, nor the mics can muster anything extraordinary.
The handsets muster just an average call quality, both in the earpiece, and through the microphones. The Z2's earpiece is strong enough, but the voices are coming in a tad grating and unnatural. The Z1's earpiece loudness is just enough at the high volumes, and you can easily recognize the caller's timbre. The two noise-canceling mics of the Z2 are able to weed out the ambient noise, but relayed our voice to the other end hollow and flat, though with an adequate volume. There is a second mic on the Z1, too, which is used for noise-cancellation, so your callers can make out what you're saying even if you happen to be in a noisy environment. On the other side of the line, callers are mostly pleased by what they hear from the Z1, getting our voice in a strong and fairly clean manner.
Sony managed to sneak a large, 3200 mAh battery, in the 8.2mm chassis of the Z2, compared to the 3000 mAh piece in the Z1. This capacity is more akin to a phablet, and Sony promises "outstanding, class-leading battery performance," citing the Z2 juicer as good for 19 hours of talk time in 3G mode, against 15 hours for the Z1.
The screen-on times we measured with the Z1 in our battery test were unimpressive, at less than five hours. The 5.2" IPS-LCD display on the Z2 is made with a more modern technology than the power-hungry TN-LCD unit of the Z1, however, which translates to better endurance. Sony cites 6-7 hours of HD video watching on a charge, so the Z2 won't break any battery life records, as this is just an average screen-on duration for an Android flagship. We will update this section when our battery life test with the Z2 is done and dusted.
With a larger, better display, faster processor, longer battery life, stereo speakers, and 4K video recording, the Z2 looks like an obvious pick before the Z1, especially considering that it is housed in the same footprint. Do these enhancements warrant the 150-200 USD or EUR price difference, though? Based on our thorough rundown with the two phones, we'd have to say yes.
The main reasons to upgrade to, or pick the Xperia Z2 before the Z1, are the better battery life, and the much improved display, which are now in line with the flagship category of the handset, instead of lagging behind the competition. Even if you don't really care about 4K video recording and real-time effects, the camera of the Z2 sports zippier performance that produces a tad better photos in some conditions than the Z1, despite that it uses the same sensor.
Overall, if you can afford the Xperia Z2, get it, but if you'd like to save a Benjamin or two, there will be better alternatives at that price point than the Z1. If you already own a Z1, and are considering an upgrade, the move to the Z2 will be worth the price difference, as you will be getting more in every aspect, and the most glaring omissions of the Z1 now stand corrected with the Z2.