If the goal of the product is to hide a compartment. I think it does it fairly well. Most people are not going to stick anything in a power socket, other than a plug. If this looked like the other outlets in my house, I would be happy with it. The only thing that is required is that you be able to accept a plug and not power anything. So it is at worst and annoyance to someone.
Really the only downside is if kids see you unlocking it. However, I would think that you would secure the room before opening a hidden storage like this, so I really don't see an issue.