I used to have title of the application on the icon in the panel, that would not work with the vertical panel, in the meantime I mostly switched to only icons so the reason keeping me from using the vertical panel disappeared.
I put my panels horizontal to the top on all my PCs for ergonomical reasons. Most programs have their UI and most of their options in the top bar, so that just makes sense to me.
That would *definitely* not work for me. I have my browser tabs on the top, when I move the mouse quickly to the top it goes and rests right on the tab, if there was another menu there I would need to hunt for the tab. Basically now I just move the mouse all the way up and then left-right to select a tab, if there was another menu on top I would have to hunt for vertical location of the tabs too, there's nothing ergonomical about that.