I didn't do a side by side test, but the first thing I noticed was how it handled skin tones. The image was much nicer than Canons by far. Next, I cranked up the ISO to 3200 and set the white balance accordingly. I was using the kit 14-140 lens, and the image was pretty sharp, and still was decent at 3200 considering the high ISO. The thing I don't like is that it cannot go up to 6400 ISO.
From what I hear, some hacks have low light capabilities of the FS100, and can create a very very sharp image with high mbs.
The build quality was pretty meh, and to be honest, I didnt even know how to change the aperture. Its setup kinda weird, but I guess it wouldn't be to bad to learn after a few days.
Im thinking of going with a Tokina 11-16, 35mm, 50mm, 85mm, and a 135mm.
I just don't know if I can get rid of my canon yet. I don't know if I have the balls to. Someone give me some input.