Revolver fans usually have both. The older Smiths were a little more refined, mainly because their actions required hand fitting. Rugers with their solid frames are theoretically stronger--but what'll blow up either one will blow up the other. A competitive shooter or commercial range owner who rents out both brands may find that Ruger revolvers will take more abuse or use before repair is needed. A steady diet of full house magnum loads in .357, .41, or
.44 magnum will cause either brand to wear rapidly.
So, in the long run, which will last longer? Doesn't matter because in the long run we'll all be dead.