I've used both. For me, it's touchpad, no contest. I can never get really comfortable with a pointstick, eraserhead, etc. Also, while I can mostly get used to the "drift" problem that's inherent in most sticks, it never really stops bugging me, just a little bit.
I play guitar, so my dexterity can't be all that bad -- but using an eraser head just makes me think of trying to build a picture frame with a 16-lb. sledge hammer.