if you swung 100,000 pounds into the side of that box it may survive but i doubt the foundation and anchor bolts do. I do know that there was a jim giles saferoom in joplin that made it through. im just skeptical about paying 5 grand for one of those or 3500 for an underground one. not trying to whore up your thread.
I have pictures of one that took a direct hit in the May 2011 tornado out in Piedmont at Falcon Lake. It was the only recognizable part of the house still standing. I was skeptical until I saw that.