Hi there, I wanted to buy this for a long time but there weren't enough informations on the web about this keyboard (with built in mouse) functionality on PC.
So after nearly a year I bought it and it is awesome!
It is very similar to old notebooks and recent Lenovo notebooks with "thinkpad", if you want a very small keyboard to use also on the sofa and hate touchpads this is the right choiche for you!
The keyboard is very small and has mouse ball in the middle and two mouse buttons:
Caps LOCK has LED! (very first wireless keyboard that has this for me!) The left rhombus button is the windows button, the right rhombus button is menu button (very similar to right mouse click)
By pressing "Fn" you have access to ALL "playstation blue buttons" and these buttons are seen as a gamepad buttons on the PC! I installed a little program "controlMK" (compatibility mode Windows XP) that maps controllers buttons to anything! I have added: center mouse button (Fn+F1=triangle), scroll up/down mouse wheel (fn+trackball up/down=left analog), pag up/down (fn+up/down arrow=D-pad), "home"/end buttons (fn+left/right arrow=D-pad). If anything else useful comes to mind I won't have problems adding them!
KEYBOARD WILL ALSO WORK with tablets, smartphones, etc (HID profile).
Imagine using this on the sofa, awesome!
Also for using music exercise programs like Guitar Pro easily without need to change position and/or drop the guitar:
Do you like that? 
ps: also no typos on this message is a good start (grammar errors don't count!) 
EDIT: there may be sometimes when the mouse moves slowly vertically when the trackball is not being touched, trackball it is very very sensitive, a very fast and easy fix is press and hold the PS button until the drifting disappears (usually 4-5 seconds).
Persona 5 on PS3, I won't need next gen!
