I don't know that I would throw topearl under the bus so quickly, I always have one rule when dealing with china, they are out to take your money. They generally don't care so much about honesty because for some reason it doesn't really seem to make a huge difference to their bottom line.
I generally deal with low end pearls, and I find that topearl is one of my favorite suppliers for my site, yes, they aren't quite as good quality as the pictures show, but that is normal in my dealings with china. when I make larger purchases, I make them take a picture of the actual lot that I am purchasing, that way I can see what I am getting, sadly, the thing I didn't like about topearl is that their customer service department does not do discounts when they mess up your order and their website is not programmed to limit orders to amount on hand, therefore when I wanted to get some akoya pearl necklaces at some sick price, it allowed me to pay for 50 of them, but they actually had less than half of that on hand. When I contacted them about this in response to their e-mail they didnt give me a discount despite my insistance upon it, but then they had already charged me.
I have dealt with all sorts of asian companies that offer the best prices for what they have, and generally I find that they all overstate the items and give you something just slightly less than what you thought you were getting, I then but a little mark-up on it and sell it as it is. I had great success with doing that with thaigem.com through a now defunct program called siammarts, which allowed you to put up thaigem's inventory on ebay with a markup. After getting some stones from them I realized why their feedback was so bad they oversold the products. I simply went in and listed exactly the same items accuratly and people bought and were very happy with me.
Honestly, I find the same thing from every asian country no matter the business, when it comes to lower end items. Remember, you get what you pay for.
So, in my experience, I rate them average, plus where else are you going to be able to get akoya pearl strands for less than $3?
(no, seriously, where? I'll buy some)