You're welcome! I hope that others can weigh in on the issue of whether and to what extent you'd get less than one redeemable mile for each mile flown in cheapest economy on US or AA. That's my impression, but I'm not certain. To find out for sure, you could call the airlines themselves or post questions about this at the AA and US forums here on FT.

I didn't know about US being tough for redeeming miles. (And, as you probably know, to the extent you can redeem US miles it need not necessarily be on US--it would be possible to redeem on UA, CO, Lufthansa or other Star Alliance partners.) My harsh comments about US stem from the horror stories I read here on FT and on the horrible experiences that my brother and mom have had flying them.

In my experience, AA is pretty good for redeeming miles, though of course as with any airline the further in advance you do so the better.