I've only just got one, so don't know how likely it is to fall apart though - although it won't be getting used all the time. I think it might be the nature of the tips for capacitive touch screens - the stylus' use a rubber tip which is softer than traditional a traditional stylus.
I've got the griffin stylus. Just remember that writing with a stylus still isn't like using pen and paper since resting your palm on the screen will cause the tablet some confusion. (and the pound land ones are only good for prodding the on-screen buttons for typing).