put it this way.. The 980 bt is a 780 with blue tooth. Still a nice unit. For some audiophiles, its just not enough. With the 880 you have the ability to go active if you want.
I just got my 9800 installed. I'm VERY happy with it. Everything about this deck I like. I'm pretty pissed that my f'n phone doesn't work 100% with the BT but that's far from the Decks fault.
I'd recommend it to anyone who doesn't need the audio capabilities of the 880