Discover what our clients have to say about their experiences with us. Our testimonials page is a showcase of success stories, happy homeowners, satisfied sellers, and contented tenants. Read on to learn how we’ve turned real estate dreams into reality for our valued clients.

John Diamantopoulos is my real estate agent in New York City and will continue to be. I will continue recommending him and only him to anyone that I know who is thinking about purchasing in Manhattan. I must say thank you to for making my transaction as effortless as possible in what we all know can be a difficult market to enter. Thank you very much for your time. Best Regards,
by Dave Natale
, The Rolling Stones
John more than fulfilled our expectations in that our apartment, in a down market was sold in a week and a half and at a price considerable above the listing price. We were previously listed with another firm for months without any activity or offers. Similarly our purchase of a larger apartment was handled expeditiously and in a matter that gave us great confidence. John’s knowledge of the Coop process was very impressive and made the process very smooth.
by Dr. James and Theresa R
Over the past 25 years, I have sold several real estate properties and had the fortunate experience of dealing with top notch brokers. However, the experience in dealing with John in the sale my property in NYC exceeded my previous expectations and set a new standard for other professionals in the field. He sold my property at an incredible price in less than 2 weeks. If there is a Real Estate school, were the craft and the art are topics for discussion, John should be the professor! He understands sales, negotiations and the value of building contracts based on value as well as trust. Without hesitation I recommend him to any seller in the current Bust or Boom economy.
by Michele S
In a down market John did a wonderful job and in record time. In our case he was able to sell our apartment while comparable apartments in and around our building remained on the market unsold. John was able to get a higher price for our home while the other comparable apartments were actually lowering their prices below what we received! John listened to what we wanted and knew just how to accomplish it. If we ever buy or sell again we would use John without hesitation!
by Howard S
John aggressively marketed my apartment in a declining market, taking personal responsibility and commitment for all aspects of the sale. Under difficult market conditions, he sold my apartment at a record high for the building and area. As a result of his efforts I had multiple offers at asking price within weeks of listing while other comparable properties in my building and area were on the market for months getting less! Additionally 2 ½ years ago John was my Real Estate Broker helping me find my home. John was able to substantially negotiate the price down on my purchase thus getting me a very high rate of return on my investment when he sold my property. With two-fold appreciation I highly recommend him.
by Martin E. F
John is a true professional. His skills in marketing of the apartment are excellent leaving no stone unturned. Unfortunately we had initially listed our apartment with another firm without having any offers or activity only suggestions to reduce our price. Upon calling John within one week we had offers and by the second week the apartment was in contract with offers above the ask. All this transpiring while the market had been deteriorating. John is truly a professional and excellent broker, with unique personal qualities. He is very hardworking, reliable and trustworthy person and best of all he has become our friend. We highly recommend him without hesitation.
by Agnes and William L
John marketed, showed and negotiated the sale of our apartment beautifully. From the excellent quality photographs, brochure and precise floor plan at the outset to the open houses he arranged to actually getting offers (6 in less than 6 weeks on the market) and negotiating them to the maximum John was terrific to work with. He is professional, precise, dedicated and really passionate about what he does. He is always available for questions and to talk through developments and he went out of his way to know every detail about new improvements in our building or anything else that added to the appeal of our apartment. We highly recommend John Diamantopoulos.
by Michael Tagliati and Tracy H
Selling apartments in New York is a trying experience. I had been previously listed with another firm for ten months without any offers or activity. John's proactive approach has been professional and distinct from the "let's-list-it-and- wait" method of most other brokers; his dexterity in the co-op market has made the process smooth and effective. I recommended John to apartment-owners, as I see how hard he works to ensure that sellers obtain the best price at the shortest time possible. My apartment was sold within one and one-half weeks of his engagement in a rapidly deteriorating market at $10 thousand above the list price. This may sound too good to be true, but I knew I could trust John for the job when I heard about what he done for a friend and neighbor in my building.
by Gersan Z
, Board Treasurer
John is a dream and somewhat of a miracle worker. Not only has he negotiated a deal in a few days, but he has found several buyers who exceed my asking price. He has completely put my mind at ease. At every step of the way, he has made the experience painless, leaving detailed messages every few days to update me. From the get-go, John promised that he would move the apartment quickly and that there would be minimal work on my part, and he's more than fulfilled this. I highly recommend him.
by Nandini D'S
John’s truly amazing in every aspect. John greatly optimized the value of my apartment saving me thousands in the process. His advice in dealing with the renovation and touch up work more than paid for his services. He swiftly obtained a price far beyond expectations. During the sale John demonstrated uncanny mastery in terms of the Co-op process and which candidates could pass the board. John’s work ethic is so tremendous I could not be happier and recommend him fervently!
by Jeff K

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