>but they don't have a native answer to shipping

I am not quite sure what this means. I had a jail a few years ago and I remember there was a utility to "back" the jail up so you could put it on another system. Are there constraints with that utility. It seemed to work, maybe I am forgetting something ?

In any case I still think Jails are much better than the things Linux has. To me, it is creating a jail that is more difficult. There were ports that made it easier, I used one of them, but that port was abandoned at some point. I think it was "ezjail".