A little comparison I did recently of the three cameras. This test is mainly focused on sharpness and moire. Both Canons had a Cinestyle profile loaded. This makes the images soft. But that's what you have to do in order to have as little moire as possible with Canon DSLR's (even with the new 5D Mark III as seen in other videos). I did only some contrast correction in post.
The Pana GH2 was on 24P Cinema mode (Daylight pref), nothing hacked.
After that test I bought myself a Panasonic GH2. For wide shots the GH2 is just looking much sharper and this almost without moire.
You can download a mp4 file in 1080p on Vimeo (compressed at 12 MB/s) to watch it on a big screen.