I've never seen a Nex 7 or used an A700, but I have an A900. Maybe the A700 and Nex 7 work the same way.
On the A900, if you set the menu choice "Ctrl dial lock" to "on", the camera will go to sleep. With this setting on, to wake up the camera, you need to half press the shutter button. Once awake, everything works as normal (the control dials are only locked when the camera is asleep). Once it goes to sleep, you have to hit the shutter button to wake it up. This is occasionally, but rarely a problem. I occasionally turn this setting off (mostly if shooting fast moving things where I want to always be ready for a shot), but leave it on otherwise. The eye sensors are disabled when asleep and the control dials don't change settings on you while walking around with the camera on your shoulder or around your neck. I find these much greater advantages than the small disadvantage of having to wake the camera manually with the shutter button.
John