I think that if a thief takes that extra couple minutes on the home of an ETS'er, and the occupant is home, it's probably gonna cost that thief dearly! Again, I'm just going by some crime stats I read, not sure if they're accurate. I'll defer to your experience in that area. One thing I will say is that every minute you cost the guy makes it that much more likely that s/he'll be discovered or interrupted during the B&E attempt. And really, that's all that locks or security systems can do. My dad did construction for 45 years, owned his own small company. I worked for him as a kid, and I can tell you there ain't much you can't get thru with the right tools. What will stand up to a sawz-all, chain saw or splitting maul? In an extreme case someone can run a vehicle thru your wall. All you can do is harden the target as much as you can.

The 5.56 rifle is a sensible choice, if you're at home to use. And if you're prepared to face all the ramifications taking that step...not a trifling matter, to be sure.