Here's my list:

- No "MacOS like" panel
   In KDE3 had the possibility to use the context menu of applications 
on a special panel
- Sideband on the menu when in classic style
   There is no longer the option to display the sideband on the left 
side menu
- There is no way to use an large button for main menu (as kbfx)
   You can change the button icon from the main menu, but if image is 
large, it is resized to a square

Note: Translation from portuguese helped by Google