I purchased my Chronomat Evolution TT from them. They are on eBay and chrono24. They also have their own website. Lots of good reviews on eBay. At the time of my purchase, there were zero negative feedback for them.
First contact - after checking with the experts here on the legitimacy of the watch, I gave their office a call and talked directly to managing director Ilya. Negotiated an acceptable price. Nice professional chat. And he was patient to answer all my questions. Email responses were also quick enough. I bugged him over phone and emails, almost daily for one whole week until I received the watch
They sent a PayPal invoice to which I made the payment. The only delays in the process were due to inter bank processing. Also received a PDF copy of the invoice for my records.
Serials intact. All papers with boxes received. As expected, warranty booklet didn't carry the seal; they were also upfront about it. Extremely good packaging and speedy overnight delivery. Also took care and advised me against shipping on weekend, as advised by their insurance company. They also were upfront about sales tax if I was to pick up the watch in NYC.
Though I am still skeptical about diamond district sellers, I would deal with these guys again. They are a legitimate business establishment. From what I was able to gather, they are not a wholesaler of sorts but their collection of watches is very niche and selective. From their eBay history I see they have transacted very expensive timepieces. They have a history of doing business in NYC.