As always it depends. If that one improvement is paid for by more hacks (not just small inconsistencies), you start thinking. Adding hacks is linear, but their destructive effects are exponential because they start to interact. These places typically are never revisited but covered in more crust.
What if your colon surgeon bragged "Yes, I forgot the instrument in you, but the polyp is gone, so celebrate the improvement and shut up!"?
What if your colon surgeon bragged "Yes, I forgot the instrument in you, but the polyp is gone, so celebrate the improvement and shut up!"?