I've been away for a week and have been using my new H8's fairly extensively during that time but have not had a single dropout so far - connected via Bluetooth to my phone, an HTC One M8 (which uses AptX).
I haven't got an iphone I can try but I think I still have an ipod touch somewhere so I will see if I can try that and report back as to whether I have any issues as this might help narrow down the cause of the issues others are experiencing.
I also haven't experienced any feedback noises when adjusting the earpads (and I have tried quite hard to reproduce that problem since seeing it reported here).
I have however discovered that because the headphones are on whilst being charged - if I try to charge the H8's from my laptops USB port, whilst simultaneously listening to audio via the headphone jack, there is a lot of high frequency 'digital chatter' type background noise introduced via the USB power connection (which probably says as much about the poor filtering of my laptops 5V DC as it does about the H8's - but it would not be an issue if they remained powered off whilst charging). It's not loud, but it is significant enough to be distracting during quiet passages of the audio.
Overall I remain pretty happy with my H8's though.
Martin.