I've got a S5 and the 5S and i can tell you know unless the light is all but perfect then yeah it might just edge out the 5S, but soon as those perfect conditions change then that when you start to see the shortfalls of the S5 camera, while the 5S can take perfect sharp images in low light or cloudy days the S5 struggles badly, more often than not images from the S5 camera come out blurry unless you keep perfectly still, the 5S has no such problems even in very low light.
So camera wise the 5S wins because it has no trouble at all taking pictures in all lighting conditions.
Well that's not been my experience. There is no blur with my S5. The only place the 5s beats it is in low light. Outside the S5 is better by far. Maybe it's the screen on the 5S but in good lighting pics just lack the detail that pics from the S5 give.