As swagmeister said above, the 686 is regarded as one of the best .357 Magnum revolvers S&W has made, especially if you like stainless guns.
The 686-4 is regarded as the best version of the 686: Revisions -1, -2, -3, -4 were mechanical improvements over the years. -5 & -6 were cost-cutting and built-in safety lock revisions (IL or internal lock). The -5,-6 are still great guns but your was the peak where looks and mechanics were perfect.
I own a -5 and -6 with some mechanical and cosmetic upgrades. Congrats on your acquisition.