My brother has a 4" GP100 and I have a 4" S&W 686+. When we go out and shoot together we both shoot both of them and they both perform equally well, about the same accuracy and both have good triggers. The 686+ trigger feels smoother to me in double action and is a bit crisper in single action. The 686+ has the edge also in firepower because it holds 7 rounds vs. 6 in the GP100
When compared side by side the Ruger looks "beefier" but is in reality only 1/10th of an ounce heavier than the Smith.
While we both can only count the rounds run through our revolvers in the 100s and not the 1000s there is much evidence out there that they both will probably be guns that will last a lifetime with a little bit of care.