Tabs on side shrink, slow and no scrollbar
As it is now tabs placed vertically are unusable, because tabs shrink to the point where you can barely select any... Font size shrinks and with my bad sight I can't read titles, icon disappears as well! One solution would be if you add a scroll bar on tabs strip when placed on the side. And lock shrinking when tab can fit only the icon and the title. But the best solution would be implementing "Windows list" panel from Opera 12, so I would just disable tab strip entirely. Simple list with opened Windows with a list of tabs in tree, like folders.
i too would welcome a tree-style vertical tab list. As it is, the vertical setting for tabs is not really userfriendly, but I guess in a future release they will fix it. At least I hope they will. for now I use ctrl-q to cycle through tabs. It's not perfect but it works.