I have one of each, one bought new in 2016, one bought used that was made in the mid 90's. I love them both and there really is no noticeable difference between the functioning of either firearm, apart from some slight sticking of the ejector rod in the used one, which I knew about when I bought it, partially because of interest in learning how to correct that minor problem. Having shot many rounds through newly made S&W revolvers with the lock, I personally don't believe the hype and don't see the lock to be an issue mechanically speaking. Aesthetically, that's a whole other thing that bothers many people, but again it doesn't really bug me much. Both my 64's have the locks, by the way. I suspect both of them could be handed down to my grandkids just as functional as they are today, and I would trust either of them to keep me safe. You can get some GREAT deals on used ones, and any gunsmith can work on them if you ever needed it. Or, spend a bit more but know you're the sole owner, and have Smith's lifetime service policy behind the purchase. You picked a great revolver either way.