When you look at actual sensor sizes you find:
The 5DM2 (FF) - 36mm x 24mm (864mm squared).
The R1 M (S35) - 24.4mm x 13.7mm (334.28 mm squared)
Epic MX (S35) - 27.65x14.58mm (403.1 mm squared)
Epic Dragon (S35) - 30×15.8mm (474mm squared)
So as you can see, an actual FF sensor is basically twice the surface area of the new Dragon sensor. Red does not currently, nor have they announced any release dates for, an actual FF camera. All of Reds cameras now and for the foreseeable future are S35.