It's kind of a "Catch 22" situation, if you aren't armed and someone breaks into your house you will probably get killed and if you are armed and you shoot the assh*le, if he survives he can sue you and if he dies you get charged with murder in the first degree.
Again, in Florida and some other states, a mans home is his castle. Someone breaking into your home is in most cases lucky to get out of the situation alive. He cannot sue you so no need for a head shot. I have to admit our law has gone a wee bit to far in that If I just feel threatened by you (no threat intended on your part), I can shoot you because I am in fear of my own life.
(That is something you really have to be able to prove)