The SSR was built specifically to meet IDPA's specs for the Stock Service Revolver division. It was designed for competition with a lightened trigger,
which MIGHT make it easier to fire unintentionally in a high-stress situation. Hopefully that's not why you thought the SSR's trigger was 'night and day'
better than the standard 686. E.g., A stock 686's trigger can be worked by a knowledgeable gunsmith to make it smoother... without being lightened.
I wouldn't say the SSR was easier to press than the regular 686. It was just smoother. I felt like the regular 686 was quite "grind-y" in its trigger pull. The SSR was as smooth as my bottom many (many) years ago.