Its nice to have a combo. I have automated systems as well as discretionary trade. By discretionary trade I mean a well documented plan with good odds and probabilities that a computer just plain and simple can not exploit. I also have automated systems that I trade systematically. For example coming off DT I will run them taking shorts only etc... I find that I can always outperform a system but its nice to have them generating some profits on the side that provide some diversity to my overall plan.