From the single run of calibration frames that I used for my testing (there may be some variance if I did another run as there always is) I was getting 11.93 bit at Gain 75 and 11.25 bit at Unity. Now every camera is a bit different as well and if I run it again it may be different also.
Ray uses a Gain of 100 so your thought of half way between the two may be very well on the money
