The sensor is the same as the F3 a famed sensor that people still love today, and its a 444 12 bit 2k sensor, however on the FS100 you can only get 420 8 bit out the hdmi port or the avchd recording. Recording externally and adding sharpness in post and recording in a flat mode will give you much better downright outstanding colors. The F3 gives you the full output, but they run about 700 bucks and are an FZ mount.
I made a good living for a few years with FS100 and 700. Bought my first house with one of those. Still look great. With great lighting and optics you can still get an incredible image with these. They do benefit a lot from an external recorder like the Odyssey.
I bought this camera when it was new and used it for years on some of my favorite projects. It really was great for its time, and those videos hold up well today. They don't look dated at all.