Once the bugs have been ironed out, the features are released as stable, and once every few weeks the streams are all refreshed. You can follow all three if you want, but please note that you shouldn't entrust valuable data to anything other than the released stable stream.

What's New:

Smoother videos on macOS

Opera 45 introduced significant performance improvements to video playback on Windows. Opera 49 makes videos better on macOS. You will get smoother playback, snappier seeking, high-resolution videos will load faster and the overall video experience should be noticeably better. The new solution has positive impact on both CPU and RAM usage, as well as power usage. Improvements are more visible when playing high resolution videos. Learn more.