Thanks to Nestor from Logitech for providing me this device.
User experience note: the upper part (covering two-third) of the middle
button is the "METRO START SCREEN" button, the smaller bottom part
provides the "middle mouse button" (MIDLLE BUTTON). This might be OK
for a desktop user, but it's awful if you have a big hand like me and
make much use of it for opening URLs in a new tab or pasting stuff.
On the other hand, the middle button can be remapped and there is both
horizontal and vertical scrolling functionality.
Peter Wu