gestures in DP4 lion vs SL

Mission control is by default a four finger swipe up. You can change it to three in the preferences. A four or three finger swipe down activates App Exposé.
Show desktop is as shown in the attached pic.

 

To be honest gestures on my MacBook Pro are different than gestures on my magic trackpad. Gestures are not working correctly (sure, this is beta). I hope Apple introduces some consistency with these gestures (i.e. swiping with 4 fingers from right to left changes the full screen apps, but on the trackpad I can only use 3 fingers - which makes little sense, since there is less space on MBP Trackpad to use 4 fingers than there is on the Magic Trackpad)

 

Why don't they just let us choose whatever we want? Why does "Show Desktop" have to be a pinch? Can't it be the old four fingers up? Mission Control can then be four fingers down. I never use app exposé, so such a handy gesture as four finger swipe down is entirely wasted. Instead, Show Desktop is assigned to a much more annoying gesture.