I guess that they are fine for people that feel they have a use for them.
The last thing I want to do in an emergency is try to push some tiny little buttons in a certain order in the dark in order to protect my family. To me, they are a complete nuisance. I will lock all my guns in the safe except for the one I have with me at the time. My kids are grown and gone, but they knew at a very young age that they were not allowed to touch a gun without me being there with them. Of course, the true meaning of what I say, if my kids didn't do as I say, they got a butt warming instead of a useless time out.
These locks are (in my opinion) nothing but a "feel good" item. Unless a lock secures the complete gun, it is not a locking device. A safe bolted to the floor is a locking device. Teaching your kids is mandatory, if you aren't doing that, you are not pulling your own responsibility in life.
Not meant to offend anyone, but I personally think these locks are a joke.