Anyone have any luck fighting their Travis County appraisal on their own?

I just tried and it went miserable.

I thought I had rock solid evidence for my case, broke everything down between land value, improvement value and cost per SF showing they had me valued far higher than any of my neighbors. Pulled up comps that were sitting on the market for 90-100 days and showed that the county market values were off by hundreds of thousands of dollars compared to actual sales data. Showed pictures of construction defects with my house since they were adjusting values since my house was "newer" and therefor more valuable. Broke it all down, and argued for a middle of the road valuation, not even trying to low-ball.

County assessor came and scrolled through her document and was basically like "He has good evidence, but this is what the spreadsheet says it's worth so, yup."

Case closed. Voted with the county assessor 3-0. It was infuriating. They could not have cared less about anything I had presented or said. Told me they can't take any defects into consideration because I didn't have repair estimates (even though the argument was that my house isn't 100%, not a cost for repairs), that price per square foot values don't matter because other things like pools and land go into it (even though I subtracted land values, and I don't have a pool making the value of my house from them make even less sense), that my comps were currently on the market and so their values don't matter since it's for Jan 1 (even though they'd been on the market for months), and to basically go fuck myself. I'm not sure what I could have done differently, I guess other than pay for an appraisal or hire someone to argue this for me.

/end rant

Any else that didn't hire a company to do this actually have any success?