...and when you look at the conversion charts (miles in one program to HHonors points to miles in a second program), you'll note a considerable loss in value. Typically, exchanging 10,000 FF miles in one program will net you only 3,000 FF miles in another program.

You'll net even fewer miles when converting AA miles to HH to UA, which you would do assuming you ask for AA miles when you fly on BA and QF.

I wouldn't make this kind of exchange unless there was no chance I could use the miles earned on BA and QF. Too much loss in value.