For whomever waiting for the iPhone 5s or 6.
We saw a prototype in the secret testing room. It's have two colors. And the appearance is the same but the iOS, CPU, camera megapixel will be different.
The reason why they keep the same because of the special machine is expensive. One set about one mill. So they will use its for two generation.
The day and time for release in Fall.
For your suggestion:
If you like taking picture with your phone, you must stick with the iPhone because iPhone have better camera.
If you like playing with the Android OS or bigger scream than stay with S4 however, S4 have 13MP camera but it can't compare to iPhone.
iPhone camera lens is supplying by Sony
Now I'm satisfy with my S4 !