Personally, I'd recommend getting the 5500. It's a great little machine, far more software support available for it then the 5600, (I understand OpenZaurus is very buggy on it) Additionally, you'd be paying anywhere from $50 to $170 extra for merely a bigger batter and a faster processor, and even then you may get a defective one, meaning you'll have to fiddle with a workaround and bring in instability. For me at least, it's no question which one I prefer. If you already know Linux, then it's up to you. If you're relatively new, then get the cheap one, to get a feel for the Zaurus. That makes the price difference more in the $350 to $520 range, which may influence your decision more. My $0.02.