Can count to 30 without issue and recognize numbers up to 100, can write the alphabet in upper case, can do simple addition (due to watching sports with the old man), hates reading (like his old man) but knows some sight words, only a few verbal pronunciation issues, very energetic/athletic kid (but not ADHD type hyper), good at following directions once settled down, very social and can make friends easily, been at a "good" daycare center since just after birth.
Daycare center says to send him since he is ready. Elementary principal says we have a tough choice, but let us know he could take college credits on the school system's dime if we held him back.
If daycare says he's ready, I'm betting he's ready. But as others have said, there won't be any drawbacks in giving him another year, unless he has a group of close friends/acquaintances who are going in the fall. Then, staying home might be hard for him.
In the meantime, if I were you, I would do everything possible to get him interested in reading. Read to him every night. Get him a subscription to a magazine (Sesame Street); mail him notes/postcards in the mail; make up treasure hunts with written clues, etc. Let him sit on your lap when you read Cyclone Fanatic!
Reading is so more important than most people realize, even at that young age, and it's important for a child to start with a positive attitude. (Do NOT tell him that you dislike reading! There will be absolutely no reason for him to like it!)
Good luck. Whatever you choose, he will be okay. It's patently clear that you care about your son. You would be shocked to know how many "parents" really don't.