Hey Alien,
Just saw your post and thought I'd jump I'm because I LOVE focus peaking on the NEX cameras.
Focus peaking puts a colored highlight, sort of like a shimmering halo around high contrast areas that are in focus. On my NEX7 I can choose whether I want the peaking level low , medium, or high. You can also choose the color of the highlight from White, yellow or red (future Sony cameras offer more colors selections from what I've read). I prefer yellow myself because it's so obvious and I set the level on high because I don't use the eye piece viewfinder, but rather the rear LCD screen UW. Focus peaking is very handy because when I see the yellow highlight, it's in focus. For macro work, when you lock the focus (after you've dialed it in with auto) you can rock back and forth slightly and actually see the yellow band of light move back and forth on your subject.
To set it up:
1.Push "Menu" button
2. Go to "Setup"
3. Scroll to "Peaking Level" set to low, med, or high.
4. Scroll to "Peaking Color" (next down) decide on the color you want.
Focus on something and you'll see the shimmering highlight. Depending on what level you set it at, it will be slight or heavy.
if I use it on the surface, I set it low because I want to see the detail in my composure without the effect being too heavy (I often even turn it off). Underwater I just want to set up my main composure and get the shot before it's gone. I like the effect heavy so I can easily see it. For macro work, focus peaking is fantastic. I leave it on all the time. No longer a need to press my face against the eye piece viewfinder and wonder where my focal point is when I'm rocking the camera back and forth. I can see the yellow halo move on the subject's body to right where I want the focus to be and hit the shutter. Sweet.