OK, I've got about 35k miles in an Aeroplan/AC account. I also have star alliance accounts active with UA (good for TATL upgrades) and BMI (good for the cash and miles redemption option, plus I have a bmi credit card).

I can't see me putting much more business onto the AC account and i'm now trying to figure out what I should do.

I have a trip coming up that awards look good on.

With Air Canada it's 30k miles but in the BMI scheme it's only 18k miles.

Should I just go with AC (as there's no long term accrual likely there) and be done with the account, or should I take the more miles efficient BMI option? If I do the latter, what do I do to get the AC account up to something usable?

Any comments appreciated!