i've never owned a dovii or an umbee or a jag but ive had oscars, tilapias (buttikoferis are NOT african), green terrors, jack dempseys, texas, firemouths, severums, red devils, midas. so the meanest one i ever owned was a male red devil midas from the point he hit 4 inches to the point i got rid of him at 8 inches for all the casualties (including wives and other tankmates). he stood up my 4 red belly piranha for three days before they got him and they were his size.