My e-ring came from them. I can't say anything towards the quality of their repos as mine is an original, but it's just as gorgeous and sparkly as they said! I don't know about their modern round brilliants, but their old european cuts are lovely! I am very very happy with the beauty of my ring and my fi was very happy with the price!
Customer service is pretty good, and the people seem very nice. They were very good at getting the ring to him quickly even though it was just before their vacation. They also left the ring up so I wouldn't know which exact one he'd bought! The only complaint he had was that they double charged his credit card. They fixed it right away but it was still a problem for him.
ETA: We seriously could not have gotten such a nice diamond in such a beautiful platnium setting anywhere else for that price. We could have afforded a nice diamond in a cheap setting, or an itsy diamond in a nice setting. I really wanted both, a beauftiful setting with a diamond over .5 carat, so I'm very grateful to AER.com!