I hope that there will be option to switch between rounded and squared layout .
Same here - I really hope for squared tabs. This rounding looks ugly to me, sorry.
Another thing - when address bar is in focus, it is surrounded by really distracting bright blue rounded border. Either make it light gray or dark unsaturated blue (and square!) or allow change its color and appearance or simply grab its appearance from windows defaults - I hate blue themes, I hate rounded themes and now both are present in my beloved browser
And more - how to hide unused buttons (start page, submit feedback, snapshot, easy settings etc)?