And when you try to turn with him all you get are high speed stalls unless you drop the flaps a little bit, which kills your speed. That other Mustang is Supermans' plane. Not realistic at all. :(
I just set up a mission with four mustangs flying around my base with no ammo, I go up, shoot them down, no problems. Except you need to have unlimited ammo due to the very weak API rounds......