Personally I prefer the Tab Bar hidden on single windows it's more minimalist and allows the toolbar to be more compact.
The side effect of course is one can't see the page title, you could "simply" use your existing tab hover as Safari does.
I realise I can select "Hide Tab Bar" on a single window to get this behaivour, but that wasn't at all obvious, I only discovered it on a related feature suggestion here.
Thanks