the 9813 offers the WMA format (which you prob. wont use), file/folder search wich is a kick ass feature for us lazy people, the vdrive 60x4, and im not sure if it offers the i-personalize feature (new in 2003). i just installed this deck in my friends car a few days ago and its very kick ass.

i on the other hand will get the 9815 simply for the cool dual line text display and the black/blue is waaay more sexy then the traditional alpine black/green