All this talk about speed...back in the day, this was a hot rod for all of the WWII pilots in training, and the first serious taste of real horsepower. Many pilots would have just finished mastering the Stearman Kaydet, with only 220 hp engines. Jumping into the AT-6, with its 600 horses, was a major step up. Putting the aircraft in a dive, and taking it down low, buzzing corn fields, even if you're only indicating 200 mph or so, it still seems like you're going fighter-speed.
From the book Fighters of World War II, by Jeff Ethell and Robert Sand:
"The AT-6 was the first dose of real horsepower given to Army Air Force Cadets and they took to the beefy trainer with unbridled enthusiasm, much to the horror of local townspeople who were constantly buzzed and chased at all hours of the day and night. It was intoxicating to ride behind 600 horsepower with the canopy slid back and the landing gear tucked up. A pilot's first taste of "rat racing" in trail, leader trying to shake those following, came with the Texan."
"Once we got into advanced training with a hot 600 hp airplane, we flying cadets considered it the hot rod we never could afford during the Depression. We could cruise about the Texas plains after dark, harassing train crewmen to the point of serious injury. We would spot a slow freighter ambling down the track, fly ahead of it for several miles, turn and meet the locomotive at cab level, and wait until we were right on the engine before turning on one landing light. The engineer would know that he couldn't avoid a sure collision, and order the fireman to jump before the "other train" hit. The engineer promptly slammed on the brakes and ground the wheels flat as the AT-6 roared overhead and we hightailed it back to base with our night flying training completed. This was great sport for both Army and Navy pilots." - William Bell, an AT-6 flying cadet.