I had an instructor at the Zoo who worked on the A-X program as a developmental engineer assigned to the A-10. During the course of the year he would indulge us with stories of the flyoff and how the A-10 ended up winning the competition.
For example, the slats inboard of the landing gear and the strakes along the wing root were a direct result of hot gas ingestion resulting in flameouts of the engines. They first started modifying the airframe with the strakes, when that didn't work the engineers put the slats on and other modifications as well until the problem went away.
The one story that he repeatedly told that I doubt would ever fly in today regarded tests to determine the amount of FOD that the engines would ingest on an unimproved airfield. Since the A-9 had intakes at the wing roots, the engineers thought that the hazard for FOD was pretty high. To determine the susceptibility of each airframe, they parked each aircraft over a smattering of corn flakes on the tarmac. Each aircraft was run up and lo-and-behold, the A-9 sucked up the cornflakes off the ground like a 3 year old. The A-10's cereal remained in its place, unmoved by the mighty power of the TF-34's.
He claims that that test helped cement A-10's place as the A-X competition winner.