I hate that I will accidentally swipe between open applications or get the charms bar. In my opinion this should not be a function of the trackpad, only a function of swiping on the touch screen. At the very least make it an option. I have a very hard time seeing and feeling where the edges of the track pad and a worse time discerning between the left and right buttons. The boarder line needed to be 2-3 times as wide as it is to make it easier to see. It is also easy to activate it and end up with the typing cursor in a completely different location and then you are having to figure out how to fix what you just typed.
Other than that it works fine.