I have a no-dash 6-inch 686, and I have no intentions of getting rid of it. Some few had to go back, but when I called S&W and asked if mine needed to be sent back, a techie asked me to get the gun, then, when it was in hand, he had me cock it and something else I don't recall at the moment. When I told him what happened, he said, "Nope. You don't have a problem. You're good." He told me that very few needed to be returned.
The no-dash model, of course, was the first issue of the revolver. Smith had been beaten up on its quality control and was intent that the 686 be up to Python-like accuracy. And indeed, the first wave were tested thoroughly and were found to give the Python a run for its money. This was done by tightening up on the tolerances and the QC.
From what I've heard from subsequent 686 owners, the accuracy of these guns has remained top notch, but I think the first wave got a great deal of scrutiny. I'd love to get a 4-incher, no-dash, as I prefer the wood grips, chromed parts and integral front sight.