for what it is worth, I put one of the Brownells/Wolffs reduced power main springs in most every Smith I shoot, I have never had any issues whatsoever with light strikes, from that change only.
When I have bought a new Smith on internet and trigger is really light, I usually find that someone has loosened the strain screw, I have played with that myself and have found that will get you light strikes very quickly.
YMMV

Chris