Most users seem to stick with the default settings rather than reverting to the Classic interface found in previous Windows versions. But you might want to change the delay you notice when you click the Start menu. I see no reason for there to be any delay when I click the Start menu. The default speed can be adjusted with a quick Registry hack.
Go to the Registry key HKEY_CURRENT_USER\Control Panel\Desktop\MenuShowDelay. The default value is 400. Set it to 0 to remove the delay completely, but if you do that it will be nearly impossible to move the mouse fast enough not to activate All Programs if you mouse over it en route to your final selection. Pick a number that suits your style, make the change, and then test it until you find a good compromise between speed
and usability.