Very strange marketing with the new motor. This should really be an excllent focusing system like many have demanded for some time now, but you'd hardly know it from the material. DC doesn't really mean much (Direct Current motor does not exactly sound awesome, like Silent Wave Motor), and worse the cheaper Canon AF motor is also called DC motor, which could lead to confusion. This was a good chance to call it something like MD (magnetic drive) that would sound impressive as well. And trumpet it more, "a lens with a revoltuionary new patented focusing motor that alows silent, instant, and accurate autfocus with advanced magnetic field technology, while allowing full-time manual control". But instead the DC acronym is just stuck into the name and the press release mentions SDM; you'd never know it was something new and different, let alone what the benefits are