[shmerl]

>If you're going through all your music and converting everything to Opus, don't. It's another lossy codec and you will lose more sound quality (it will sound worse). Keep what you have. If you're really concerned over sound quality: use something lossless, like FLAC.

I'm buying music in FLAC, and store it as master copy. Then I convert it to Opus for actual playback. If better free codec will come out, I'll do the same thing, using FLAC as a source. So FLAC has its usage.