Just installed an Alpine 9857 so I could drive my IPod, and the DCI is a really slick piece of technology.

My first look at the instructions left me a little cold since not all the wires are described on the diagram in the instructions. However, once I figured out that all the non-DCI wires have labels right on the wires themselves, things went smoothly. There were quite a few splices to solder and shrink-tube, but when I installed the head unit and the amazing matchbook-sized DCI, everything worked right away. The speed-sensitive volume control is great. I'll have to get used to NOT working the volume all the time.