I bought this as a replacement to an OEM radio/cassette/multi-cd player. The reason being that the original audio system would not play CD-Rs reliably, or CD-RWs at all. It had no auxiliary input so playing MP3 was also impossible. It had no DAB and no long wave band. The Kenwood KDC-DAB41U has all the above. It gives good control over audio settings and even knows what tracks you are playing on CDs and MP3 discs created yourself, provided they were tagged when writing them. I am very pleased with the sound quality.
I have had it connected up to my steering wheel controls and this has worked perfectly.
The DAB works reasonably well, although I paid for an aerial adapter so that the car's own aerial could be used rather than rely on the one that comes with it which sticks to the windscreen. With DAB you either seem to get a strong signal or none at all and sometimes it takes a while for the system to lock on to a signal. The other thing to note with the DAB is that the system claims to switch between DAB and FM automatically if a DAB signal is not being received for a channel which is also being broadcast on FM. In my experience (so far) this does not work. I've checked all the settings are correct. For this reason I have given it 4 stars instead of 5.
I haven't yet used the USB or auxiliary ports as I've had no need to.