I've processed and ate a lot of Jumbo Browm/Pharoah mixes and Texas A&Ms ("Amys"). There really is no difference in the flavor or darkness of the meat, although the Amys do have slightly more breast meat. Four Amys dressed weigh a total of 1 pound, for Jumbos dressed weigh about 14 ounces.
When compared to chicken both types of coturnix meat have a stronger aroma and a more delicate texture.
When compared to chicken both types of coturnix meat have a stronger aroma and a more delicate texture.