Anyone have experience with a good way to store an AR for home defense that is:

1) Kid Safe - Not just hidden (doesn't have to be hidden), but locked.
2) Quick Access in an Emergency.
3) Doesn't require major installation (cutting into the wall, etc - simple mounting and drilling is ok)

I've searched and seen many different things advertised, but would love to hear from anyone who actually uses them. Pros and cons, reality versus ad claims, etc.