I feel that there's no reason one should go out of their way, or sacrifice other good moves, to teach a Pokemon Rest and even combine it with Sleep Talk. I think the only obvious exception would be teaching these moves to Snorlax because, well, it's Snorlax.
Even using Sleep Talk is risky in critical situations; there's still a 1/3 chance that Sleep Talk will just use Rest again while you're already asleep.
I see people saying they include Rest in their movesets to various Pokemon with high HP, but I can't figure out why Rest is a better option than a Max or Hyper Potion or a Full Restore. And yes, I am aware that Rest is free and Potions cost money.
Just curious. Any thoughts?