Help with Zeiss 24mm!

On the NEX-7, which is what I have, OSS is disabled by going to Menu->Setup->SteadyShot, and then selecting "Off".

In my opinion, OSS helps when shooting handheld even at the 24mm focal length. You'll be able to utilize somewhat slower shutter speeds which, in turn, allow you to use a smaller aperture (if desired) or a lower ISO. This is especially true for handheld landscape shots where there's not a lot of movement.

OSS should be turned off when shooting on a tripod.  (Therefore, if most of your shots are taken using a tripod, you won't benefit from OSS since it'll be turned off.)