1: The face quality and feel was terrible.
2: The way the face opens caused me to have to hack up my dash kit for it to fit properly causing a huge gap if I wanted to put another HU in its place. I've heard of a buch of other people that have had this problem as well.
3: The menu's are terrible.
4: The usb made all sorts of noises in frequencies up high that your tweeters would pick up, like a snapping sound.
5: The output was always inconsistent, on the highway I would have to turn it up to 65/70 for it to be consistently loud, whereas with my current 9887 and old 880prs and 860mp I have never had an issue with output.
6: The single dial to operate everything, it's near impossible to change tracks or do anything productive while driving with that big *** single knob/switch.
Thats mostly the big stuff, I can't think of the rest but I'm pretty sure there was a bit more.