The battery was horrible, it would discharge around 5-6pm. Later it would discharge around 3pm. The only way to prevent it was to switch off all features that were touted in adverts. It was unable to play music without stuttering until I got Poweramp and set it to largest buffer and highest priority. It spontaneously bricked at night and I lost all my contacts and had to restore them from my iPad. SD card would disconnect at random moments until I stuck a piece of paper on top of it. TouchWiz was gross and I haven't discovered Nova yet. Camera was just plain bad.
It's really a big thing for me to consider another Samsung phone after all that. But my brother switched from Z5 and looooves the S7. I've got a Z5c with 2 GB RAM and the memory management is terrible. I think I'll get an S7 when it's my time to upgrade, in August.