If, based on encountering new information, or simply based on a re-thinking of the problem, or based on an actual change in circumstances (e.g. new regulations passed), I wish to completely replace an answer (written by me) with entirely different content, is it better to delete the old one and add the new one, or to paste the new one in place of the old one via an edit? Or should I feel free to do whichever I prefer?
One issue is that if I've linked to the answer in other answers, then if I deleted and replaced it, I'd have to go change those links (assuming it was still relevant to have the link), and those other answers would get bumped up to the top of the home page-- this would be avoided if I cut and pasted the new content in.
Another issue is that "comments" may be attached to the old answer that might be of interest to anyone thinking about the question, and it might be better not to lose them by deleting the answer-- I could always add a comment noting that substantial changes had happened so the comments may not be exactly relevant to the current answer but are still of general interest--