Graphical tabs simply offer visual indication. Graphical tabs are to browsing what application icons are to the dock. I can glance at a tab and see what it is more quickly than reading it. Additionally, the side-tabs make it much easier to see what the tabs are. Once Safari reaches 15 tabs or so, the names of each tab are so small they rarely give the user enough info without having to mouse over each one. Furthermore, after so many tabs are created, I have to click on some arrows to see the rest of the tabs listed out.