I wrote this back in 2015. Post #7.
An appeal based on uniformity is the way to go.
PM me if you have any questions or need some additional help.
https://www.theoutdoorstrader.com/threads/property-value-appeal.906370/#post-4572664
This.
99% of taxpayers don't know about "uniformity" There is probably not a digest in Georgia that can withstand a "uniformity" attack, mostly because even the assessors don't understand it, and will testify that it doesn't apply to them.
Check the record of the Board of Equalizers, some of them are good, most of them are toadies power tripping.
If you go to a hearing, make sure to subpoena as many people in Assessor's office as you want, and ask them to produce as many documents as you feel are necessary, including those related to uniformity.
It's a cliche, but in tax appeals, it's the squeaky wheel that gets the greased, unless you're in Fulton County , then it's the tax commissioner's palm that gets greased.
Follow Jaybird's advice, appeal to Superior Court. You can do it on your own, but the county has to use the county attorney and he ain't working for free. He can bill more than your tax bill by lunch time.