The 20.7MP camera is pretty good on my brother's Z1C, and compared to my dad's 5s the quality seems very good. In low light conditions however I think the 5s pulls out a bit. Hopefully the Z3/Z3C will iron out these problems and refine the camera a bit more, but we will need to wait for reviews.
For sound HTC is probably the best in my books, in both speakers and headphones. But that 4 "Ultrapixel" camera lets the phone done. It does the job, but compared to other flagships it could be better.
Build quality on all phones is pretty top notch so you won't have a problem there.
So I would say for Android, it would be between the Xperia Z3/Z3 Compact, Galaxy S5, Galaxy Note 4 or the LG G3. Play around with these and see how you feel, they're pretty much very similiar in terms of internal hardware, you just need to see which camera feels more right for you as well as their software UI.