I got Kramer from a humane society and neutered him about a month after I got him when he was about a year old. We enjoyed, truly enjoyed, 15 years together. We spent so much time out and about, and when he was (finally) reliable, off lead around lots of distractions. There may have been intact females in heat, but I don't know that. I never had to worry that there would be little Kramers, and he never seemed to miss out on anything either. We were free to do what we wanted within local laws and ordinances but I never allowed him to go farther than my voice.
He lived until he was 16, robust, vigorous and healthy until the last 5 weeks, happily overseeing a pack from age 9 on. I never had to do rotations or limit anything in his life. He was as free as a dog owned by a super neurotic could be.
I think that is a gift I can give to them-others feel totally differently. Same with the girls-over say 12 years, they don't have 2 months a year (2 years total, 1/6 of their life) that they have limitations. If you are going to breed your dog, well, yeah...of course! But if not...
I realize you asked for people who have decided NOT to neuter, but wanted to explain, beyond the supposed health issues either way, the propaganda, etc, why I feel I get so much, all the time, and so few limitations with my animals, for the very limited time they are with us.