Windows 8 Boots faster, wakes up faster. The GUI seems about the same to me, a lower end machine may find the GUI to be faster as Aero is gone.

You just need to consider the Windows 8 menu screen like you would the Windows 7 start menu. It just covers the entire screen. You can ignore all the Windows 8 full screen applications for the most part, I am sure they are nice on a tablet but not on my 27" desktop screen.

I find it easier to move between a Windows 7 machine at work and my Windows 8 machine at home then between XP and Windows 7, the old work home combination.