I bought the Herd GT-77-ATV model. It is built to accurately broadcast fire ant bait. All of the Universities that are doing experiments with fire ants are using this model. I am going to be using Amdro Pro. I don't cut hay for animal feed off my fields and I don't have any grazing livestock in them. Check with your local County Extension Office to see what they recommend for your area.
I am not looking for instant knockdown power. I want the time release so the workers carry the bait deep into the nest and contaminate the queen and other workers before it knocks them down. If you can kill the queens, then you have killed the nest. That is what Amdro Pro does.