Longtime Opera user here, continues to suit my needs, but the beta still needs a fair bit of work:
- The new Tab Stacks feature is almost what I've wanted for some time, needs some more depth to it (labelling, pinning, and loading sessions as stacks in particular), and to undo the wonkiness introduced to the tab bar behavior in general
- Nice to see Opera join the Extensions party, but slim pickings so far, need to see what gets developed for it to measure its worth.
- While the Mouse Gestures overhaul/visual feedback is a nice idea, it currently forces a much more rigid input of the gestures than what anyone seems to be used to.