Hello, I am trying vertical tabs and I find them very useful. They unclutter the view, allow to see full website title on top, gives better readability on other tabs titles. Collapsed view is also very convenient as well as tab grouping. But vertical tabs could also give some more vertical space as they are listed on a side not on top. I suggest to join Omnibox and site title in one row when vertical tabs are used. Now site title takes a whole row of real estate on screen but is basically empty as most screens are wide nowdays. Vertical tabs have great value specifically for widescreen displays which lack vertical space. If you would replace Omnibox with site title while scrolling and show address on mouse hover as well as allowing editing it, also move window control buttons the same toolbar row, it would leave more vertical space for site content.
This is what I have in mind:
