Thought I would add a reply to help others. I laboured over whether to buy because of reported audio issues. I'm not an audiophile but I like good sound and notice annoying audio quirks. Once noticed they cannot be ignored!
In the end I though I would chance it. Bought from three UK online. Had it two days.
So far so good. Screen is sensitive. 'sensitive touch' which allows use with gloves is excellent, allows ghost finger which is good for basic things if dirty hands. Works fine.
Tap to wake, not had any glitches so far. Works as expected.
Sensitive touch does switch off when charging and not reenable automatically which is annoying.
Camera is quick, and functional. Image viewing has issues as described. The camera is average compared to any other mid to high flagships. It works but can't replace a proper camera for holiday snaps. With an 7s I could leave my camera at home. But it costs 300% as much!
Now audio. There is a noise. It is antenna interference when headphones attached. In my phone it is extremely minor. With even V low-moderate volume it is inaudible. With volume at 0 you can hear it.
The volume varies with headphone impedance, which makes sense. Clearly the WiFi and Bluetooth are inducing a current in the signal path, post amplification. Higher impedance, more current, relatively quieter interference. I tried with two iem Sony's. Ex71 and ex650. Both, with phone on 1 volume, interference is no issue (if listening to Chopin, or V quiet music u can hear it). With Dennis hd25 70ohm. The interference is less noticeable but, the phone struggles to drive the headphones as well, so it's swings and roundabouts abouts.
If I switch off Bluetooth, there is an improvement. If I switch if WiFi the interference goes away altogether. So it is the WiFi and Bluetooth antenna's causing it.
I suspect it could be a minor ground look, due to the ground pole of the headphone jack, touching the phone body. I'm unsure if the top section of phone is part of antenna array? If so, a tiny insulator on base of headphone jack may help, if it doesn't interfere with the fit of the jack.
The YouTube app does have a jitter and delay. All other video playback is fine tho so it is something to do with the way the app works. YouTube on chrome is flawless.
All in all I have no issues with this device and will keep it. For audio it's not the best but is good enough. I can download my music and switch off WiFi and Bluetooth to remove the noise if I'm listening to classical.
The build and features of the phone are so good for the price I'm at a loss why I would buy anything else. The only exception being that you may not like android, or what a bleeding edge camera. But I could buy this phone and a DSLR for less than an iPhone....
Hope this helps some people.