I had to send something back once (yes, all the way to China), but they were very nice about it. This was a long time ago. The first order was good. I was just able to make one necklace out of two strands, having to discard about 40% of the pearls. The price was great and the pearls that ended up in the necklace looked terrific.
The second order cost twice as much and was half the quality. There weren't quite enough good pearls out of four strands to make one short necklace and I had been hoping to make a long one.
They are very nice people. I agree - only rely on photos and keep your fingers crossed.
The World Is My Oyster!