I grew up (in America) saying "different than" because that's what my parents said. Later in life I adopted "different from". But to return to the inexplicable-preposition discussion at the start of the thread, professional jazz musicians say "to be on a band" rather than "in a band", especially when referring to big bands. "Yeah, I remember that cat, he was on the Ellington band for a while." "Say, weren't you on Maynard's band back in the 80's?" etc.