Z3C or Z2 topic

I'm looking for a phone for my wife; camera and battery are what she states are most important, but general performance she will care about.

Barring the obvious screen size, resolution, and PPI differences between the Z2 and Z3C, the specs seem quite similar. Was wondering what "real world" performance differences people experience, if any.

Anything that should push me one way or the other? I'm leaning Z3C mainly because its newer.

Sent from my OnePlus One