My safe doesn't have a biometric lock. But it is electronic. [keypad] I looked for quite a while at different safes, not really wanting an electronic system for the reasons already mentioned. Ultimately, I did buy one anyway due to the back-up opening methods. I've had mine about a year now and it works well. There are actually two back-up methods: one is a 2-key deal, meaning you have to have both [different] keys in order to bypass the lock; plus, the electronic locks use...electricity...from batteries located inside the safe. If the batteries go dead, you have a little battery box you can plug into the lock system. Of course, you need to remember where you stored the little box [about half the size of a cigarette pack] or the special additional key. I've experimented with all three opening methods and they work flawlessly.
All meaning: I have gotten over my initial reluctance to have the electronic lock. At leas with my system.