The Sony F3 is basically a Sony EX-1 with a Super-35 sized sensor and a PL-mount, so you can put cinema lenses on it. I was a 2nd AC on a shoot with this camera a few days ago. My first impressions of this camera are rather good. It has a very clean image (less noisy than EX-3, probably due to the larger sensor), good sensitivity (500 ISO at -3 db, according to Abel Cine
), and overall is pretty easy to use. I don't care for the viewfinder in the back, and the camera we used was a little finicky about the lens data being transmitted from the Sony lenses that are available to buy with the camera. Like with the EX-1 and EX-3, you have to watch for overexposing highlights, but its not a huge deal. Eventually a S-Log gamma option will be added, which supposedly allows you to preserve more of the dynamic range.
I think the Sony F3 is a very good middle ground between DSLRs (low-end, lots of issues) and the RED or Alexa (overkill and too expensive for most purposes), if you want a shallower depth-of-field than traditional video cameras.