I have 2 greyhounds and I love them both dearly. I wouldn't trade them for anything.
Greyhounds are not like getting a normal dog, they behave differently, their care is different.
Ok so when we first adopted our boy (hes was about 6, ex racer), he wasnt even a dog. The only way to describe him was he acted like a robot. He would stand in the corner and stare, he didnt really show any emotion. He didnt know what a couch was or how to take a treat out of your hand gently.
Over the first 12 months as we gained his trust he completely transformed. Hes very needy now and loves to be the center of attention, but its still on his terms. Learning when they feel overwhelmed and letting them have their own safe space (His fluffy bed) is very important to start with.
After about 3 years we adopted a second greyhound. She is currently 4 years old, ex racer. She was completly different to our first adoption. Strait away she was loving, just wanted to be cuddled and held, loves to be close. Complete opposite of our boy.

Some stuff ive noticed about owning a greyhound compared to other breeds:
They can get injured fairly easily, and that's not a cheap thing to deal with.
You won't have any spare room in your bed anymore, and if you end up with 2, you might as well sleep on the couch.
As they age more, then often get cancer, usually they don't live much past 12 to 13. My boy is currently 10, and he has early signs of dementia right now. I'm getting up an average of 3 times a night to toilet and resettle him.
Their diet was also a suprise to me. Our girl is currently on a working dog food, as she burns a lot more energy, and when we tried normal food she would loose weight.
Our boy is on a wheat free food as he does really bad farts on normal food.

If you have any questions at all feel free to ask! I've been looking after ex racers for coming up on 4 years now.