I am a data point. I frequently have up to 100 tabs open, which are often interesting articles, music or gadgets i stumbled across and want to keep for reference. I use a tiling WM so i only ever have 1 browser window. But with the extremely efficient Pentadactyl buffer (== tab) search i could type something like "hack chrome" and this comment thread would be one RET, or a TAB (== next completion) RET away.