Hah. Well, that and a good fullscreen browser for OLED displays were my main motivations. Both of those are addressed by FF now.
Also, the vertical bar can be set to whatever width you want on both, I think. On FF (which is what I'm typing this in, so I can check) you can shrink it down so it only displays a single row of icons.
The idea is to hide it altogether when you're not using it, in any case, but you can definitely make it as skinny or skinnier than tthe top bar.