I have both and a 586. the triggers need to be done on all new Smith's. I think the 686 is better than the SSR for high power loads. The SSR is better for low power compitition. I do like the easy change front site on the 686. You can also polish/pimp out the 686. The lighter front end of the SSR does feel a bit like a 3".
Good luck on whatever you decide.