Personally speaking, I have not looked back since taking the plunge 5 years ago.
I do miss the odd thing about the mob, such as the camaraderie, and the alcohol fuelled jolly japes, and the big toys to play with. I don't miss the stupidity of bulling boots combat high, nor penny pinching procurement.
I suppose I was lucky, I joined a company full of ex-servicemen initially, and worked on some major telecoms toys. Made a nice transition.
I now have a FAR higher standard of living, and salary wise, I left as a sergeant, and now earn Lt Col/Wingco money. I would not have made such progression in the mob.
I've seen more of the world since I left than when I was in, but that's just because of my job.
For me, it came down to why I joined. I joined in the Cold War to serve my Queen and country. Having achieved the mission, I left to further my family life. No regrets whatsoever about joining or leaving.
The grass is just the same as it was on the other side of the wire. It's just that I'm allowed to walk on it now. Oh, and say what the fcuk I like about dcikhead officers. In my company, not being a "yes man" has taken me far (literally!), and I have the mob to thank for that.