I have an 8-gun cabinet. It's really not at all flimsy for what it is. It's inexpensive, it keeps the closet neat, it keeps your guns from getting banged up and rusted. It keeps oil and fouling off our clothes.
While it won't absolutely positively prevent a dedicated thief from stealing your valuable firearms, it will make it almost infinitely more difficult than just grabbing them from where they're leaning against the wall! If you're home during a break-in, it will keep a burglar from just grabbing one of your own guns and using it on you.
It will also keep kids, inebriated party guests, and others from messing with your firearms. This can save a life.
I did get a safe, too, later on, when I ran out of room.
If I were looking at the 14-gun, I'd consider the Sentry 14-gun safe, which I also have. With an electronic lock (MUCH more convenient, and makes it useful for quick access to defensive guns as well) it was $409. It's not super-heavy for a safe, but it is a lot more solid than the cabinet, and it's more flexible if you have carbines, scoped rifles, long shotguns, etc. The positioning of the standoffs in the Sentry works better for me. In the cabinet, I had to put a board under the floor foam to get a 10/22 to reach the standoffs, for example