KO system good enough for the serious player?

I've mastered the KO prefered system, but not the full KO. I play with red chips at the moment but want to move up to green chips. Is this a good enough count system for the serious player moving up to higher limits or should I learn a new stronger system? Should I master the full KO, even though it is not rccommened in the book?
I recently bought proffesional blackjack, and blackbelt in blackjack for info mainly but dont know if its worth it to learn a new system.
Thanks.