I noticed that sometimes people have an R4 with 2 cards (one white and one black) and some others have only one or the other. My question is: What is the point of having 2???
You mean two shells? Well if you have a dark coloured DS use the dark shell, if you have a light coloured DS you use the white shell. My M3DSS came with both shells, as I have a black DS I use the dark shell.
Most places only ship with one now, only the first batches came with both, what colour you get I don't know.
Sorry, a little off topic but I would be cautious about ordering from modchip store. I placed an order for an M3 but still have not received. It's possible that the R4 is in stock. Just wanted to relay my experience, your experience may vary.