Numpads push your hand out of position, so if you say, need to type WHERE or make a quick cb report it'll cost you precious moments to move your hand back into position, type it out, and go back to numpad to continue spamming east.

Oh well, the difference isn't that big of a deal when you're familiar with the game environment - in quick chases 3/4 of my commands are inputted before the previous set of actions finish.