Like Eric, I’m still using my older GoPros because they still work.
Sometimes FCP will re-wrap footage when using the Import function, but you should never lose quality. I will say that when I use my GoPros, I transcode those files to ProRes prior to import using EditReady, simply because the native GoPro MP4 footage causes playback issues in the timeline. EditReady will do several things – it pulls in metadata from sidecar files (if present), it will stitch together segmented clips, and is pretty flexible. And fast.
When importing anything, I choose Leave in Place, or I drag & drop from Finder into keyword groups. This allows me to more accurately catalog my storage media, and find assets that I might need for future projects.