I am writing about the phone htc desire 820q after using it almost 13 months and I must tell this is the best ever phone I have ever used.
It has a octa core processor and 2 gb ram supporting it as for camera 13 mp rear and front 5 mp altough the quality of rear camera is not great but its not bad too.
It has a battery that can run through out the day and let you comfortable also with ultra saving mode you can take juice out of it for some more time .
it has a heating issues if you play games for long time or stay in a area where the signals are not proper otherwise it will never say no to your processing or multitasking. in these 13 months it never hung even for a single time . Display is very gud and audio is loud and clear at last HTC is HTC best in class of hardware and services