I have one of each and love them both...
I got the S&W used from my father and he had purchased it used. It has a butter smooth trigger and is capable of shooting much better than I.
The Ruger was purchased barely used and the trigger has smoothed out through a lot of dry firing and putting about 300 rounds of live ammo down range. It is also a great shooter.
I don't think you can go wrong with either!