I have the PDC without the camera on my '06 M3 and its okay. Recently got rid of our '07 mdx with backup camera but no PDC and it was better. I now have the 2012 X5 with both and its even better. If I had to choose between the two, backup camera would be my preference since you can always see what's going on in the back. Going by sound alone is hard especially if its in the 1 ft range where the beep is continuous.