Although announced as a perfect match I still wonder if the F3 shall be worth the Gemini 444 according to its native resolution.
I read an article about the native sensor used for the F3. It says as follows:
"The CMOS sensor in the F3 has 1220*690 pixels in Green and 610*345 pixels in Red and Blue
This should work for 4:2:0 but curtainly not for 4:4:4. You'll get a great sensitivity and dynamic range. Also better S/N ratio and minimal aliasing. There is slight disadvantage in sharpness and resolution."
I would conclude that the Nanoflash will be good enough for the F3 and you gain too little (2 bits depth) by using 444 recording. Unless I go for the S-Log option, I would not need a Gemini-like recording device.
Is this a rational conclusion?

I don't think those resolution values are accurate. The resolution of the imager exceeds 3k.

From what I've read the camera may not completely resolve 4.4.4 but it will be close.

If you look at the recently released BBC report, its Zone Plate test makes it appear as though there are an even number of R, G, B pixels on the sensor.

look at page 10.

http://thebrownings.name/WHP034/pdf/WHP034-ADD68_Sony_PMW-F3.pdf

Here is the thread about this report http://www.dvinfo.net/forum/sony-xdcam-f3-cinealta/493829-f3-bbc-report.html

If you read the entire report, you will see glaring mistakes; however, the Zone Plates cannot lie.

Personally, just the S-Log output is worth it not to mention the ability to record 1080 60p.