Cardio and Weights, no doubt about it. It's the perfect substitution.
I'm surprised the rotation has you doing a circuit workout with weights, AND CTX upper body in the same day? That's a lot of upper body work! Are you sure the rotation isn't suggesting that you just do the cardio portions of Body Fusion? If that's the case, then CW also has an all-step premix on the dvd.
Cheers,
Sandra