i love the fact that how innocently you mention >70 tabs
yeah please give me a real use case for 70+ tabs that doesn't involve a PHD research paper :)
TVTropes. (Or Everything2, or Wikipedia, or...) Basically, using the tab bar as a "to read next" queue as you spider a heavily linked graph. The real solution to this, though, isn't reducing memory usage, but rather avoiding preloading tabs opened in the background once you hit a certain threshold.
That's a lot of tabs. But yes, I've noticed that as well.
It also fails to display >70 tabs in a single window, depending on screen resolution.