Hi have used this phone i.e ( HTC Desire 820Q) it is good phone wich is by a well known brand HTC I have used this device and not found it hanging at all.
I have found its boom sound effect helpfull during watching movies and while playing games. This HTC device also looks good,
It has a very good camera in it and editing software pre install in it it has got android lollipop update and soon I think so that it will get marshmallow update. We can play hd games like Asphalt 8, dead trigger 2 in it without hanging issue it is a good phone according to me