This is the main point. I outfitted all the exterior doors on my house and workshop with Schlage keypad deadbolts, and replaced all the levers with keyless types for exactly this reason. And I don't carry a house key, ever.
The Schlage unit beeps on unlock when the battery gets low, long before it dies. And it lasts three years (on average) on a single battery, so it's not like it's a common event. You're far more likely to be locked out due to forgetting your key (with a traditional setup) than you are using a keyless deadbolt. I haven't been locked out of my keyless setup yet, and barring amnesia, I don't expect to be.
Completely agree!
I have put the Schlage keyless locks on every one of my exterior doors and I have never had a problem in the years I have used them.
When I first tried it out, I worried about the batteries just dying and locking me out, but as you say, they let you know long in advance of impeding failure. I actually had the battery in my first one last nearly 5 years!
I have just change the batteries every couple of years now and I don't have any issues.
I will agree with the others and say that keyed levers are useless and just a pain.
Even with a residential grade deadbolt you can be fairly secure; you just have to realize that the typical failure mode isn't the deadbolt itself, it is the jamb with the 1/2" screws and the crappy HD "metal" door that splits wide open.
I have experienced this a couple of times when my mother's house was broken into.. A swift kick and the door splits along the edge and the jamb is just torn out...
I pretty much remedied this by pulling out the inside casing and inserting a 3x12" 1/8" thick sheet of steel drilled out for the dead bolt and about 8 screws. I inserted it behind the jamb and filled any remaining gap with thin sheets of plywood.
Then I ran 3.5 screws through everything into the studs.
I also installed a U shaped piece of steel that keeps the door from splitting... With trim back in and the door and saddle painted, you would never really know it has been beefed up.
I not saying this will stop a battering ram, but it will take some work to get through...