Magnesium has a crazy effect on my sleep, very very noticeably deeper.
Not necessarily more restful, but deep and I don't remember anything. With B6 it's deep but more interspersed with vivid dreams.
I take zinc with them too, my own zma stack basically. I'm not sure the zinc has a direct effect on sleep, I take it for testosterone benefits.
These made me realize that legal vitamins and supplements can have much more than a subtle effect.