On one of my questions, here, Coriolis effect and Cyclones, there were originally 2 answers and I decided to select what I thought to be the best answer.
After I had done this, the answer I did not accept was edited dramatically to become far more comprehensive than it was previously. So much so that I believe it now surpasses the original answer I had selected as best.
This posed a dilemma for me, because on one hand I didn't want to remove the +15 reputation points from the user who at the time of my decision had clearly posted the best and I appreciated it a lot. But at the same time, the new answer is now better in my opinion.
What is the SE etiquette in this matter? Should I constantly update the best answer to match new edits, or once I've made a decision, should I stick with it?