Any ANG guys

Promotions in all active and reserve units are "good ol' boy" to a certain extent, and they always have been, but UMD slots are what shoot you to the top, or lock you in place.
After four years active duty, I went from E4 to MSGT in six years, and retired with twelve years in grade. However, the choice was mine. I could have gotten my degree, which would have allowed promotion to one grade over the slot, or I could have cross trained.

I loved my AF job, and while more pay is always welcome it wasn't worth retraining, and at my age I simply had no desire to go back to school as both my military and civilian jobs required too much of my time.