The Cylinder Std was replaced with a much improved design.
It certainly is different looking -- but how is it improved or better for the end user? I've read that it streamlines manufacturing because it's part of the frame and not a part that must be put in to place. Should we assume that because of that...it "strengthens" the frame in some manner?
I suppose I am saying: of all the different quirks any S&W revolver has ever had over the century... I don't recall the old traditional cylinder stop being one of them.