And for the heck of it I shot the new Browning Illusion at the same draw weight and it shot 278.2 FPS
Now that surprised me, especially considering the other bows you were comparing it to. I haven't had a chance to handle one of the new Illusions but considering the looks of it I might have to. Sort of looks alot like a Switchback.
Anyway, was the draw length the same on all the bows you shot? If not then that might explain some of the unusual speed differences.