I just picked up a lightly used 638-3 and so far no finish issues. I am sure it will wear but I am not worried about it. Pretty much every S&W j frame I have owned has started showing lots of wear in a few months. Just adds charm as far as I am concerned
Probably the most durable finished revolver I ever carried was an LCR. Carried daily for two years and just started to show some wear on the front edge of the front sight.