Of course no security is 100% be it a security door, a deadlock or alarm system. They are deterants. And a would be thief really doesn't want to take any more time than necessary to carry out your TV. So if there is something that will cause delay he will be looking at the place next door that has the welcome mat out and the door open.
Will people get in even with a security door. Sure. But alot less than without. I would not consider a unit without a security door.