J.
We put a pressure gate on my older son's door for a while. It provided a barrier to replace the crib, but demonstrated that he wasn't going anywhere (but could see out) and it worked pretty well. He didn't fuss too much about it. Once he got used to the idea of having to stay in bed, we removed the gate.
But I think all the sleep stuff depends on the child. My second son has always been more challenging about sleep-related things but I'm really starting to believe he just doesn't need as much. (but we still make him stay in his room.)