I would tend towards 3.5. Great deer at any age. What is the chance you pass him and he lives til next year?
He is running with what appear to be older age class bucks(non-rut, bigger necks, probably 5.5+). He could be on his way down at 7.5-8.5. Cover up his antlers and he appears to be a mature doe, so I am guessing 3.5.
I would guess him as only a 3 year old in Georgia. That is in Brooks county right? I believe he would have a little more defined belly if he was 4. I am no expert and they can fool you during the summer. He is not a 2 year old for sure. His chest is too developed for that. It is super hard to let one walk like that in Georgia but if you got good nutrition, which I believe you probably do, and he makes it another year, he would be a Booner next year. That is my goal on our land anyway. I am trying to let the young super stars live. That's the only way to get them big. Good luck but I would love to see what he would look like in a year.