I have to disagree Rahga. Hex is much harder for me to use. Maybe it is just me. We use Octal all the time in our PLCs. Octal becomes almost second nature after a bit fo time. Maybe hex would be as well if I used it more.
Sad thing is, the fact that octal is used shows what really old school technology we use. Converting from decimal to binary is extremely easy to do now a days. A $2 calculator does it in fractions of a second. Unfortunately the FAA is so far behind that their computers would probably puke if we tried to shove a nine at them.