Personally, I much prefer the Marbles. It has windage adjustment, where the Lyman does not. I have 6 Marbles on rifles ranging from Marlin 336's, 1895's, Win '92, Win '73 and two Colt Lightnings.
I just purchased an original '73 rifle, and the Marbles precisely fit the original holes drilled and tapped in the tang 125 years ago, even to the screw size and thread pitch.