I bought a B Stock Sundown SD3 12" from them 2 months ago. Was nervous at 1st but was such a good deal that I said screw it, very glad I did. I still cant find anything wrong with it. Cosmetically it was perfect, there were like 1-2 extremely small scratches on the motor, but I'm talking tiny, like the only reason I noticed them was because I was looking so hard to find anything wrong. Got me a bit nervous cuz then I thought something might be wrong mechanically, maybe a coil tick or something, but its performed perfectly too. So they must have crazy strict QC guidelines.
I think anyone who would have paid full price for my sub wouldn't have had any complaints.
In other words dont be worried about buying b stock from them, you wont be disappointed!