I hope I don't get in trouble for the reveal, but I have some inside information. The DC09 was supposed to have a spring loaded power nozzle extension to go under low furniture. It was promising until they found in in-home testing that cats decided it was a toy and destroyed them. The DC10 was an innovative brushless turbo nozzle that sent vibrations into the rug. It was effective on carpet, but in the focus group discussions, some claimed that it was offensive looking (i.e. looked too much like an adult toy). Not all prototypes make it to production.