I didn't realize Rexair sold more than one model at a time. The new Onyx has several improvements. Some of these changes are a new power nozzle with side-mounted belt and a better air path, LED lights in the tub, changes to the handle switch to lock, and I believe a more powerful motor. The Onyx has a brushless motor I do think. Not sure if the older ones had that. A number of people here have bought it and can tell you more.