I have had that speedpad for a couple years now. When it was first released I actually returned it because the software was to flaky but then a few months later after new software was released I bought it again and have loved it ever sence.... I fact I have bought it for all my gaming frineds for their birthdays over the years.
It took me a couple weeks to get used to it but when I did I felt my playing skills go up a notch. On the down side I have allot of trouble going back and playing on a normal keyboard.
The greatest advantages are (1) the ability to have 4 to 8 buttons on your thumb. When I need to sprint I push forward on my thumb, back go's slow, up is jump and down is crouch. In very heated times you can quickly tap the tumb down button twice very rapidly to dive to the ground. (2) The scroll/throttle is nice (but I personally don't use it in FPS'ers). (3) The ability to have three sets of keys binded to the pad which you can switch on the fly. Nice for games where you jump into vehicles or use specical weapons. You can hit a button on the speedpad and the entire pad would then be configured for that specifc purpose.
Arty (aka Lowdrag), if you want to use anything I just posted be my guest or if you want I can add parts to the review. I just don't have the time to write a whole one on my own. I know Wolfseven also uses this and likes it, though he did have some technical issues at first to deal with I think....