Everybody has their favourites.I have to say that I stick to an old favorite which is the NCH Switch Sound File Converter, you can drag n drop select the quality you want and pretty much whatever format you want to save it in, and the choice of saving in the original place or select a different one (it will also delete the file after conversion). I it so easy to use that even I can use it. The downside is its not on here but is on lime. Sorry if im not supposed to say that location. Its just another alternative that does opus files
Got to admit ive not used a lot of the others as I was happy with Switch, but I guess you have, I only mentioned it as a possible alternative, adding to the information already given. As you so rightly say "everyone has their favorites" but if you dont try them ( i must admit i havent) you will never know which one is better. I tend to stick to programs that have the simplest to use with just basic features that tend not to crash as often as the more elaborate ones do, although most are quite stable nowadays. I think im still doing things the hard way by todays standards as I started with computers way back in the 70's, (guess maybe you weren't born then). I still have a lot to learn but hey if it works for me why give myself a headache and start changing things. Sometimes the old ways work and always pave the way for new ideas.Everybody has their favourites.
Their functionality is all much of a muchness:
drag n drop
choice of target directory,
choice of quality,
delete original after convert
overwrite target if already exist
etc. etc. etc..............................................
Download a few and use the one that's feels nicest to you.