The iPhone 6 battery is better than the 5s but a good margin but not leaps and bounds. After using it over a week I would say you get an average of 1-4 hours vs the 5s depending on how you use it. I'm sure the z3c will be better when I compare at the cost of waiting longer for it to charge.
Thx. Give us a comparison on speaker when the Z3C if you can. I wasn't very happy with the Z1C speaker. I know it is water-proof which blocks the passage, but it sounded way too tinny. The bigger Z1 was not much better either. The dual front speakers should help but I don't expect it to be that much better than Z2.
As for battery life, the Z3 series have over a month's worth of standby mode (38 days/920 hrs on 3G standby). Generally 2-3x longer SCREEN OFF TIME while radios are on than most current smartphones while they're on airplane mode. While SCREEN ON TIME is claimed to be fantastic ranging from an insane 14-15 hr (claimed by GSMArena) for Wi-Fi browsing and video playback.
Snapdragon 800+ series can power down each core to sleep or 300 MHz while on idle. I don't think the A8 chip can do this although it is it built on the 20nm than 28nm find on Qualcomm's. Most cores stay at a higher frequency even while the screen sleeps and no apps are running. Also efficiency from KitKat, near 500 mAh bigger battery than iP6's, Sony's own custom battery optimizations, and the power efficient displays they use should all play a role on why the Z3C topples most 2014 smartphones' battery life out there including the bigger Z3 and iP6/6+.
First time ever for me when Sony got closer to making the perfect smartphones and they didn't really disappoint in any areas like they usually do! Of course Sony will probably go directly to Snapdragon 810 next year with the Z4/Z4C release and tick off would be buyers of Z3/Z3C after six months.
Sony - just annual flagship releases please?