Yeah that was a great video, the best disc comparison I've seen. They toned it back into similar ranges I'm used to throwing at, and it is exactly what I experience. A 300ish flat Firebird throw can be 375' on a Sidewinder or Roadrunner on the right angle.
I really think most players who throw 300-350'ish can get their longest possible throws with something in the Sidewinder or Roadrunner class. I'm not saying don't bag a speed 12 for low ceilings, wind, and for a bit more distance when going more stable as the speed does help compensate, but for overall distance that lower speed disc will glide easier and fade later. Plus you can't fake the throw by torquing it over and hoping it comes back, they are so rewarding to throw clean.