I worked in the private sector for about 8 years before moving to public sector. I had worked in the oil field, where I made big bucks but just about destroyed my health and sanity with 100+ hour weeks, and then I worked for an A&E firm doing construction management. I went to work for a state-level environmental agency and was very happy with the move. I had absolutely sane hours, lower stress, actually had "fun", and my private sector experience made me a superior performer. And like you said I took advantage of a lot of training opportunities and eventually used that to transition to an entirely new branch of engineering from where I had started. And also as you said, it exposes you to a lot of employment opportunities, provided of course you are a good worker and have decent interpersonal skills.
Now I am in the federal government, which significantly ups the pay and benefits side of the equation, and at the same time I am assigned to a municipal-level water and wastewater utility, so I am seeing both of those sides of public sector work, and both are really great.
I don't regret the move from private to public at all.