In terms of cortisol control and fat loss, I think Reduce XT is the way to go.
KSM-66 is a great ingredient and has a large variety of uses but I wouldn't take it just for cortisol control.
For those looking to stack KSM-66 and Reduce XT, I really like the M-Test/Reduce XT stack. M-Test has KSM-66 in it plus a lot more great ingredients.