All other things being equal, I would direct those points towards MU (just remember, air points have much stricter expiration terms than hotel points so it's best to hold off until you have an award in mind) because CA have points have lost a lot of their relative value since CA joined *A (i.e. I can rack up UA points much faster and, with the exception of CA upgrades and a view value priced awards like LH and CX, they are functionally equivalent).