I left after just under 20 years. Some of my leaders were excellent; some so-called leaders I wouldn't follow to the pub out of choice, even if they were buying (which they probably wouldn't be, as they were only interested in stepping on heads to get their next promotion).
I have since done about the same amount of time as a civilian. Since then I've had a few good leaders and some very poor ones, too.
As far as civilian leaders go, some of the best and some of the worst were ex-military.
The military reflects society as a whole, in my experience.