Originally Posted by PumpkinSmasher

This is a good breakdown, but I would add two things to this.

1.) For AC, I don't think it's too hard to extend your miles. a.) You can get the TD card and/or b.) AMEX MR are a partner and you can transfer over at any time. Both options will extend your expiration date.
2.) There is still pretty good value with AA miles too. In fact, I'd prefer AA miles over BA avios. Yes, the availability for their own flights are pretty bad, but there are some solid options on partner flights. Especially on EY, QR, CX, JL, and even IB. You do have to do a more legwork though and it pretty much always involves calling, but some good options for sure.