My pinkie is what I use for Backspace, Enter, and Right Shift. It resides half on the aluminum, half on plastic. Plastic is a bit taller, and aluminum is a bit

My pinkie is what I use for Backspace, Enter, and Right Shift. It resides half on the aluminum, half on plastic. Plastic is a bit taller, and aluminum is a bit cooler -- if I feel that, I know it's in the right spot horizontally. When I move it for an occasional apostrophe (e.g. a moment ago for typing "it's"), I need to put it back in the right position. With an additional set of keys on the right, I can't position it properly without looking at the keyboard.