S
It's probably a compromise indeed. From tree tab suggestion thread which is finaly so linked to this one, porting bookmark bar style menu to tab would be interesting :
But
I strongly believe that the active stack should be developped, at least enough to avoid that stacking is a regressive browsering way. Today, the automatic stacking loses you more than if you no use it. Whereas the tab should be an interface to quick get in our mind which tabs are opened, the stack reduces this to only a little and common colored bar. When you add a new tab, like particularly background new tab, you don't see really changes and wonder if you have really clicked. If the current focused stack isn't developped, you lose the way to know which was the last tab that you opened or the next that you have already opened : the tab order into stack is an important information that helps you ! that's why this should be always visible since thanks to that you decide to click to another link or not, to stay into this stack or not.
I think that the current stacking should seem to the user as a independant tab chain implemented into an another tab chain.