Sigh...
I was hoping they'd keep UI, just swap the internals. That was main reason I used Opera - I feel like it's interface was much more powerful than those of other browsers, but engine performance just wasn't there.
But this doesn't bear any resemblance to Opera I knew and liked.
No pinned tabs. No 'paste-and-go'. No... nothing.
I fully understand why they did it, and it very well might be just what they needed to do to survive, I won't be looking back.
...and I was hoping to ditch Safari :(