After I ordered the A7 with Kit, I was a little disappointed with the pictures. I had to full-frame hoped after switching from the Nikon D7000 more.
I order then the two available FE Zeiss prime lenses (35 and 55 mm)
On these two lenses is clearly visible, capable of what the sensor in the A7 is (good JPG processing in the A7). Incredibly sharp and contrasty, each already at full aperture. The Zeiss-typical 3D Pop-effect occurs here. Shooting in JPG is virtually no post-processing needed. The camera processing does a very good job here.
The pictures with the Kitlinse I was never really satisfied. Resharpening was standard here. Since the ownership of the Zeiss lenses, the kit no longer was used. Also I would have liked a little more telephoto focal length. So I was unable to use not much and have letzenendes sold the kit. Now I use an old Minolta 28-135 in connection with an LA-EA4 adapter as travel zoom solution until there is a native replacement.
Advantages of Kitlinse I see in Image Stabilizer and silent autofocus. This is helps when shooting video.
The lens is very light because it consists mostly of plastic. The value is in my opinion inappropriate for Body. However, for the beginning sies doing anyway. If you want the full-frame sensor ausreizen, to get an update on eg the Zeiss 24-70er or fixed focal length lenses are not around.