Elite II and Autoset II

Does anyone know if there is a mechanical difference between the Elite II and the Autoset II? Or is the difference software only?

This is just curiosity on my part. I'm not planning to hunt for a pirate site with the software code to let me upgrade. CPAP seems to suit me fine. But I do wonder if all the information that has to be collected to run the Autoset's algorithm is known to the Elite, just not used for anything.