Guns wear as they age and get shot more and more. Sometimes they need new parts and have to get repaired. Sometimes they were not fit correctly when they were built and need to go back. As long as your repair was done properly (not a big repair job and presumably S&W knows what they're doing) then it should be as good as or better than new. If you shoot a lot and were to sell a gun every time it needed tweaking or a new part - you would be selling a lot of guns.

Again, as long as it locks up properly now and if the Cylinder does not rotate at the "neutral position" then you should be good to go.

The only time I'd reject a gun is when it goes back for repair multiple times and the same problem does not get fixed. As you stated this is not so in your case.