Some menu changes. Altitude adjustment is embedded in the calibration branch of the menu tree. The most significant change is the injection period. The solenoid on/off period is depth variable but since there is no depth sensor it responds to what effect the injection has on the loop PPO2 and adjusts the cycle accordingly. The HUD gives solid red below .5 now since 8 flashes are somewhat meaningless. There is a change in the battery saving mode that the backlighting can be set to stay on and sleep mode can be deactivated.
That's all I can think of but I haven't upgraded yet. I have not decided if I need to.