Laptop trackpads and the Charms bar
I don't have a Windows 8(.1) laptop currently but I've tried some in stores and the trackpads on them always allow you to swipe in from the right to bring up the charms bar, but unless I'm doing something wrong it seems really counter-intuitive that when you do so, you actually have to move your mouse cursor BACK to the charms bar in order to be able to actually click a charm, because the swipe gesture moved your cursor halfway across the screen.
It just doesn't seem to be worth the effort to use the charms bar with the trackpad gesture. I would like it that if you made the gesture, the charms bar would pop in and while it's visible, you can just tap on the right-most side of your trackpad at the appropriate height to activate the charm that's present there, without first having to drag your cursor back there again. I would mostly use this to go back to the start screen, and this would seem like a nice way to do it if you're too lazy to reach for the Windows key on the keyboard.
Unless, like I said, I'm doing something wrong. In which case I'd gladly hear it. I think the HP Spectre 13 sort of works like this (it has a dedicated area for this gesture on its massive trackpad) but I don't understand why not all of them behave like that. It would feel natural I think.