I bought a loose diamond from USA Certed recently (a vendor I found through Price Scope) and I have to say my experience was very positive. I''m a diamond "noobie" and I don''t have a lot of posts here, but I did endless hours of reading here before I made my purchase. What I read from most others on here was true and I can also say you can trust USA Certed.
I chose USA Certed because they had some great prices online and because they are physically located near Toronto, Canada (where I live). I dealt with Martin - very nice guy as all other reviews will say. I put a lot of trust in him with my purchase (1st ever diamond purchase) and he did not let me down. I got a great diamond at an amazing price. I had it appraised by 2 different institutions and it was valued thousands more than what I paid. My girlfriend was ecstatic as she had probably only expected something half this nice.
I''ve read some posts on here that said Martin at USA Certed does not always return emails/calls and there is some truth to this. As a first time buyer I "probably" called/emailed Martin more than the avg buyer, but I can say ~ 90% of my inquiries were returned within 24hrs. However, after visiting him in person I can understand why the odd message may slip. Martin literally gets hundreds of calls/emails a day and its just hard for him to keep up with his efficient operation. I can attest that he does try his best, but things do slip the odd time. Also, I can attest that his email spam filter may be a bit "hyperactive" because it even got me once and it was a reply from his email! Anyhoo, if you''re serious best bet is by phone, but I traded over 10 emails with him during my purchase for advice, prices, etc with minimal lag between replies. I think it''s very reasonable to expect that with the lowest prices in North America (literally) you should expect a little trade-off in service. His quality of service is great, but sometimes its hard to keep up with the volume of inquiries.
I''ve gone off topic a bit, but I will definitely be using USA Certed again and would highly recommend him. You can find out online his prices are great, but you can trust Martin as a vendor and a person as well - and this is the main reason I''ll be back (when I''m out of debt

P.S. I had my diamond set by Look Diamonds and I would not recommend them. My experience was not "bad" however I did pay a premium and the setting was avg. at best. The quality is good and the setting is nice, but it''s not as close to the Tiffany replica as I had expected. I wish I had spent more time researching this and one day down the road I will probably end up getting it re-set.