In my experience, the biggest gap in the typical apartment's layered security is that the apartment management will have keys to your apartment, and thus access whenever it deems it necessary. Most apartment leases I've seen have a clause in them to this effect. So even if you change the locks, they have to have a key. Thus, a lot of the security measures can be simply bypassed. Your apartment can be entered, searched, valuable things noted and indexed.

Good replacement value insurance and off site storage for anything you can't afford to lose is, IMO, the best protection. In particular I do not feel comfortable leaving any firearms in an apartment unless they are in a substantial safe when you are not in the apartment. They just have too much "street" value.

Cameras will help document the theft, maybe even help catch the person. They do not mean you will actually recover anything taken. I'd prefer not to take the loss in the first place.