The cable chop sounds great on paper, but when it comes to the execution it's less of a core exercise and more of an arm blaster. Also, the resistance changes drastically from beginning to end.
With this method, the Swiss ball acts as a cam similar to what you'd find on a machine, giving you the feel of constant, equal tension throughout the ROM and putting that tension right where you need it.
Endurance training may make you leaner, but it'll eat up muscle, damage your cardiovascular system, elevate cortisol, put you in an acidic state, and might just kill you.