Difference between IE8 and ie9

I recently upgraded IE8 to ie9, so I won't talk much about the performance and support for HTML5 and css3. I can find it online and I will share my personal experience:

1. ie9: The last tab can be deleted and the entire IE is closed. [improvement]

2. ie9: You can drag the new tab to use [improvement] as a new ie page]

3. ie9: the tab page and the address bar are in the same row, saving space. However, you can select the tab page under the address bar, but the effect is not good. [improvement]

4. ie9: The command bar automatically displays a row and can only be displayed on the left, occupying space [lagging behind]

5. ie9]

6. ie9: the performance is said to have improved. I use a map cluster application.ProgramAfter testing, I lost the problem of memory growth in IE8 [improvement], but I always Ctrl + k to create a new tab. Soon the browser will die, however, IE8 does not have this problem [lagging behind]