I think you mostly put your finger on it.
Those little SP .22s are really pretty clunky little guns & overly heavy for the caliber.
I'm not knocking them, please cancel the letter bombs.
I think if Ruger had rounded off some profiles & angles, reduced some weight out front, and made them look a little more graceful like the Smiths, along with adding adjustable sights, the guns would have sold better.
Denis