OK, so it is not really faster. It is better, though.
We've had replacement M1400 pens for the Motion tablet on order for months and months - they never come in. So in the meantime, we've found out that the stylus pen for the Fujitsu T4220/4215 fits the pen bay from the M1400 perfectly. Also, since the Fujitsu stylus pen has a tab on it like the Motion pen, it won't get stuck in the bay like a standard Wacom pen.
The best part is that, unlike the original M1400 pen, the Fujitsu replacement has an eraser! If you find yourself in need of replacement pens for your M-series tablet (they come in 2-packs), you can order them here.
Keep in mind that ANY tablet PC pen for an active digitizer will work on any other tablet.