The Firearms Blog has a post that shows the lengths some people will go to in order to secure their firearms in inconspicuous places. I think if you’re that worried, the easier solution is to just carry it around with you. There’s a gun in every room that I’m in too, because I generally keep the Kel-Tec holstered in-pocket, even around the house. It’s a good idea, even if you aren’t that paranoid,  because you want to remain conditioned not to stuff other objects into the gun pocket. The other issue I have with the stash method is, in homes I’ve seen that have been broken into, they’ve been ransacked. They are likely going to find your stashed guns, and then just steal the cases. They can break into the cases somewhere else at their leisure.
We have a few quick opens that we don’t currently use. I think quick opens are ideal for childproofing your self-defense guns, and we don’t have children. To prevent theft, a floor safe is the best option.
He uses a simplex lockbox held in place by a neodymium magnet. This is slightly more secure than just putting holsters in place, but much less secure than pretty much anything else. Someone could literally walk off with it and then have the gun 30 minutes later because that’s how long it takes to brute force a simplex.
Can’t you brute force it faster with a hammer and chisel?