The difference and potential benefit is the more traditional Phil rear hub is made to accept SS freewheels or track cogs; and the King hub has a narrow cassette, spacers, and a lockring - this allows you to dial in the chain line. And the cassette, if you're so inclined, allows you to run a 1x2 or 1x3 (Though that might require some quick links if you don't have long dropouts). Either way, don't worry about the weight because it's in the center of the wheel and won't affect performance (In fact the superior bearings likely offset the small extra weight). Again, good luck.