What's the difference between Ford and Epps as a Solomon's masters?

Solomon's description of the two men speaks for itself:

But I was sometime his slave, and had an opportunity of learning well his character and disposition, and it is but simple justice to him when I say, in my opinion, there never was a more kind, noble, candid, Christian man than William Ford.

Master Epps was a roystering, blustering, noisy fellow, whose chief delight was in dancing with his "niggers," or lashing them about the yard with his long whip, just for the pleasure of hearing them screech and scream, as the great welts were planted on their backs. When sober, he was silent, reserved and cunning, not beating us indiscriminately, as in his drunken moments, but sending the end of his rawhide to some tender spot of a lagging slave, with a sly dexterity peculiar to himself.