I think you'll need 5DtoRGB software to convert GH3's .mov file into Apple ProRes if you want to edit on FCP7. 5D MKIII looks good in both log and transfer or 5DtoRGB conversion.
I hope Panasonic will release plugin for FCP for the log and transfer.
preset "Standard" picture setting
Olympus Zuiko Digital 12-60mm
Canon 24-105mm L
Both are comparable high quality zoom lenses
ND 0.6 filter on both, ISO 200 & 160
f=7.1 & 6.3, WB=Sunlight
1080 30P All-i, 1/60 shutter speed
Video files converted to ProRes422 by 5DtoRGB for FCP7 editing
If you like the music, you can buy it here.