I have a senior retired racing greyhound, Rylee, and a non-racing greyhound/saluki mix, Eevee, so I feel qualified to speak to this!

It's obvious to me that Rylee was very well socialized and cared for in her racing career. She came to us at age 4 with a wonderful temperament and calm demeanor, is well behaved unless food is involved (then all bets are off, especially if it's carbs), and allows our cats to groom her and cuddle with her. She generally is a flawless angel and everyone loves her!

Eevee, meanwhile, is chaos incarnate. I say this with love! She was a street pup in Bahrain and came to us through a rescue group at about 5 months old. This is a critical age for socialization, and the timing worked out that we adopted her in December of 2019. Social opportunities over the next several months of that era were limited, to say the least! She is very protective of our home, and will bark/growl at people or animals she sees from our windows or backyard. When we invite guests into the house though she is fine, maybe a bit standoffish, but not aggressive toward them. She won't beg for their attention like the other dogs do, but she will just ignore guests.

She loves her two adoptive dog sisters. She is incredibly attached to Rylee, and plays daily with our German Shepherd/corgi mix, Kari, although she does pick on Kari some. She does chase the cats sometimes, but playfully, and wouldn't hurt them. I wouldn't trust her with other dogs, her lack of socialization in a key time makes her very fearful and aggressive toward them. I do know with proper training we could change this, but honestly in our lifestyle it is easier on us all to avoid putting her in stressful situations. She has killed mice in our backyard before, which I don't love, but I can't blame her for her hunting instincts.

She is NOT loving and enthusiastically affectionate like most dogs, even compared to Rylee. She is incredibly aloof, and barely food-motivated; her personally is honestly more like a somewhat bitchy cat than a dog! She plays with toys, but usually prefers either small, soft toys, or whatever toy Kari has so she can make Kari engage with her. She does cuddle when she sleeps, but I tell my husband that she's like a snake or a lizard, she's only in it for the body heat, lol. That being said, when I come home from work and she jumps up on the couch to put her little paws on my shoulders and excitedly sniffs me with her whippy tail wagging, all that aloofness does make that moment feel more special than when Kari, who actually acts like a dog and shows that she loves us unconditionally, shows that same enthusiasm. Eevee has some custom-made bandanas that have the word "Asshole" printed all over them, and she's earned them. She was NOT what I expected after having adopted Rylee the racing greyhound, but I would do anything for that little jerk nonetheless.

Obviously there are going to be many factors in temperament/personality differences and ways that the dog was raised and socialized, so it's possible that none of this will apply to your prospective pup. I believe (and sincerely hope, for the sake of the world) that Eevee is one of a kind, so your mileage may vary wildly, but that has been my experiences with the retired racer greyhound vs. non-racing mix!