Vivaldi is based on Opera and Chrome. I have been using it for about a year.
There are versions for Windows, Mac, and Linux.
Next best among up-to-date browsers (you can hack it to get multiple tab rows ) after Firefox Quantum portable (so you can also use legacy Firefox at the same time and which you can also hack to get multiple tab rows). And along with Waterfox classic (most FF legacy extns work) then I use two profiles of Firefox ESR 59
which enable Tab Mix Plus and a few other extensions which enabled more key customization than the whole of other browsers.