I've had one of these for a couple of months, and I'm very happy with it.
Installation was just a case of unplugging the old radio, running in a cable to the DAB aerial and plugging everything in. I'm using a glass mount aerial on the rear quarter light in a metro (it was cheaper with the aearial than on its own).
There does seem to be some confusion on another forum I read over whether the illumination actually changes when the car's lights are on, it seems only to light up the power button when the unit's off and the lights are on as opposed to dimming the illumination. It did seem a bit too bright at night when I first got it, but I'm used to it now.
The DAB navigation is better than the Pioneer unit I had in my last car , the cursors allow you to move up and down between ensembles, and back and forward through stations on each ensemble. I'm not happy with the manual's instructions for getting Traffic Announcements working while using DAB, mainly because it refers to a menu option that I can't find!
MP3 playback sounds good to me and having a pause button is invaluable. I can never remember whether it's up or down to move to the next directory though.
I can't really comment on CD playback as I've not tried that yet. The same goes for FM, as I went for a DAB unit because I wanted to listen to DAB only stations.