Mogami cable is copper, Audio Magic uses silver clad cables.
In my experience silver has a more open sound to it and copper has a bloom in the low end. Everyone hears it differently, you'd have to listen for yourself.
FWIW, Audio Magic charges a premium for their cables. I think you could probably find an equivalent cable at a much lower cost from someone here on the board.
Remember, what some of us think is better may not be what you prefer. Either cable is high quality and will do a good job. Good luck and have fun listening.