I have a 4 inch 629. It is a top notch gun. It has the lock. I also have a vintage 586 without a lock. It is a true collectors item. I do not feel that you can go wrong with a S&W revolver. I have three S&W revolvers with locks. They are all three ultra reliable. All three are used for concealed carry by either my wife or myself. I would and do trust my life to them. If you like the gun you should not be afraid to buy it.
Romans 1:16 I am not ashamed of the gospel, because it is the power of God for the salvation of everyone who believes: first for the Jew, then for the Gentile.