Containers of this type have their benefits, at least for me.
When leaving my vehicle and entering the doctor's office, for example, where I will be required to remove some of my clothing for an exam, test, X-ray, etc. I can't logically take my pistol and spare ammo in with me, so my choices are to leave them at home, or lock them in my vehicle in the parking lot. There are other examples of NPE's that present similar challenges.
A reasonably small secure "vault" type container secured with cable to the seat frame on the floor of the vehicle beats laying the pistol and spare magazine(s) on the floor in a pistol rug, or even "locking" them in the glove compartment or center console. And the container is easily transferrable to my other vehicles.
And there are several much less expensive options than the subject vault that serve in this role adequately.
I have to ditch my primary pistol most of the time when I show up for a job, so have adopted this pistol safe: https://www.amazon.com/American-Secu...09103730&psc=1
I bore a hole in the side of the safe and install an eye bolt with double nuts so it can't be removed. I padlock one end of a short chain log chain to the safe and the other end to the seat rail. In my work truck, it sits behind the seat and in my 4Runner it slides under the drivers seat from the back. No system is theft proof, but I am trying. Fortunately, I bought my safes before they started making them out of gold!
Your method is much better than most will do. The popularity of inexpensive (and usually cheaply made) lock boxes show that people for the most part don't take securing their gun in a vehicle very serious. I get it in some regards, a locked door should be enough, but in reality it's really not. Also, when just going inside some place like the Post Office for a few minutes is different than all day while you are at work and can't carry.
I still don't think the StopBox is a good way to secure and leave your gun in a vehicle. The manufacturer doesn't even describe it as a secure container. The way they describe it is a "Retention Device" and maybe to keep your kids hands off your gun around the house or transporting the gun. With the cable attached it will keep your kids from walking away with it, but it's just attached to a pretty thin plastic box.
If you have one do you think the cable wouldn't just pull through the plastic with a solid yank on the box? It doesn't look strong enough to me, but to be fair I haven't seen one in person.
I've got a Lock'er Down safe in the console of my 4Runner. I find it useful for the occasional, temporary storage of the firearm if I have to run into an NPE, but also a great place to lock up the garage door opener or other stuff I don't want falling into the hands of miscreants if they break into the vehicle.
Not a cheap alternative, though it was quite a bit less expensive when I bought it than it is now. Installs fast and easily.
There's nothing civil about this war.
I like the idea of a purpose-built safe for the console and if my AmSec had not fit under the seat, I would've gone with the console safe. Fortunately, it did fit so I can use the console for other things I'll probably never need. Price wise, not much difference. I carry too much crap in my pockets and in my cars, so space is at a premium. I may be a hoarder, but I'm a well-organized hoarder!