The difference is why I like him. I like conductors with an individual style... Stokowski, Bernstein, Toscanini... You know it's them from the first note without even looking at the cover of the album. I'm not so interested in "proper" conducting that "lets the music speak for itself".
The aspects that make Karajan so unique are a massed string tone that sounds like one big string instrument, beautifully articulated horns and a lush sort of phrasing that lends itself not only to romantic Gernanic music, but Mozart and (gasp!) Bach too. Karajan's best work is the Mozart Horn concertos with Dennis Brain, his Sibelius cycle, Bruckner, Strauss (all of them), Dvorak's Slavonic Dances and New World Symphony, and Holst's The Planets.
No denying his greatness in this film clip shot by Henri-George Clouzot...
There is a blu-ray of this entire performance along with a Mozart violin concerto with Menuhin. Get it even if you don't like Karajan. It's the best photographed classical music performance ever.