Ed,
If the Smith you fellas are talking about is worth his salt, he should be able to smooth that lock up for you, it's not rocket science. Many times the manufactured parts are on the rough side but acceptable for company standard. Many of the internal lock parts on these guns are "cast" parts that may only see a trip through a vibro or tumbler for a short period and then are assembled. Although they function properly, they have a lot of drag to them because cast parts have a "scale" or "bead" surface, even after the tumbling process. Honing and polishing all of the bearing surfaces makes a world of difference.
If your Smith does it right, you should have no want or need for a double set trigger.
BPS