Good Points You can plug a MP3 or USB stick stright into it i have a 10gb with over 3000 songs at the touch of a button. Connects to to my Fiat factory cd changer.
Bad Points It sells itslef on it 1000's of different colours you can have as a background, but i feel the display is poor and dull no matter what colour you choose.
Overall Its a cracking headunit for under £100 its no Pioneer but does everything you need, but if money is no object id go for the The Blaupunkt Memphis MP66 its the same unit but with a TFT display screen.
I purchased my MP56 to replace a ordinary CD32 unit in my Rover and have been amazed at the improvement in sound quality. Once you work out how to turn off the Demo mode it is an exceptionally good unit, both audibly and visually.
Having the ability to use MP3 discs and SD cards as well as memory sticks is just an added bonus. One word of caution make sure you have the right leads / changer unit. Blue Spot Audio are very helpful in this area.
I've got a Blaupunkt casablanca MP56 at the moment, and it is the best stereo I've ever used. The sound quality is outstanding when you have nice speakers and it is perfect with my sub. The controls are easy once you have a little play around with them. The radio reception is perfect, it sounds like a CD.
I bought this head unit to replace an old Sony unit which was difficult to operate. The Blaupunkt unit offered USB and SD card compatibility. What is not clear is that it is not compatible with USB drives over about 30Gb and SD cards that are larger than 2Gb. I have therefore ended up using an 8Gb USB stick to store my WMA music files which is rather restrictive. The unit is quite complicated and not very intuitive to operate while driving. The sound quality is OK and radio reception is OK rather than exceptional. I suspect that a good external power amp would improve things.