I think u can't go wrong with either
But I know the Dovii can dart from one side of the tank to the other side to attack a fish like a bullet. LOL seen it many times. I think umbees cant do that because they are built different. King of cichlids are the Doviis imo. They are vicious and nasty killers. A pair of blue Doviis are beautiful too. Not just crazy mean. They got more beautiful colors and shine with the ugly scary face while umbees have the cute baby face but not much iridescent to their colors or shine..
For me, I'd go Dovii for beauty with beast in one.. But umbees are cool too. Cute face on adults but the colors not as exciting as Doviis