I own both the NEX-6 and the NEX-7 and have found that when I go shooting I invariably grab the 6. Although one might discuss the lower noise characteristic of the NEX-6, I found that this was not the reason that I chose that camera. The reasons, in bullet form, were:
1. Ergonomics and control layout: I found I could select the controls I wanted to use faster and easier with the NEX-6. I am accustomed to the mode dial control and this a physical control of this type is lacking on the NEX-7.
2. WiFi connectivity: One thing that annoyed me about the NEX series of cameras is that one had to use an IR transmitter to trigger the camera remotely. The Remote Camera App for the NEX-6 allowed me to trigger the camera with my iPhone or my iPad Mini. Plus, the nice preview screen on the iPAD Mini provided a nice view of the subject prior to shooting the camera.
3. The kit lens that comes with the NEX-6 collapses when the camera is turned off. This made it that much easier to carry about.
Oddly, though the pixel count is larger for the NEX-7 I generally did not regard this as either a plus or minus. The one exception is that my wife likes to make 24 x 36 inch prints. When she knew that the photograph would be used for this purpose she would choose the NEX-7. However, for must of our family shots and internet usage, we just as soon as use the NEX-6.