Here is reality. A 3" SP101, KSP-331X, weighs 27 oz and has fixed sights. A 3" 60, SKU #162430, weighs 24.5 oz. Keep in mind that they both have the same cylinder hole spacing. The Ruger has a more masive barrel shroud; the S&W, a lugged barrel. The coil spring lockwork of the S&W J-frame is smoother than the Ruger's (I am biased here - my worst-ever QC revolver was a 4" .32 H&RM SP101. It took a lot of work to clean up it's horrid trigger!).The J-frame S&W has a multitude of grip options - the grip stud of the Ruger options are much more limited in number and style. Finally - the S&W is hammer forged and heat-treated, while the Ruger is investment cast SS. Put bluntly, it takes more cast steel to equal the strength of hammer forged steel. Both revolvers are designed for SAAMI spec-ed .357M's.
For a few $ more than the above mentioned 60, I got a 60 Pro, SKU #178013:
The fixed sights of all of the .38/.357M SP101's are also irritating. A 3" barrel .357M should be available with a fully adjustable rear sight. The only SP101 to ever be released with a fully adjustable rear sight is the new - just out - 4" .22.
Stainz