Thanks for the reply. If I do switch to AA, then I will take the platinum challenge (I made a separate post about that in the AA group). However, to switch solely because of the platinum challenge might be a bit short-sighted.

As far as I can see, the biggest disadvantages of AA are:
- AA only give 70% of miles flown for discount economy on QF (and I'll probably fly 30% of my miles on QF)
- QF give a 1000 mile guarantee (quite high) for each segment flown on QF
- Can't earn AA miles on BA trans-Atlantic (may or may not be relevant)
- Can't do international upgrades

OTOH, the advantages of AA are:
- Easier to get status. I did some more calculations, and let's say all the segments flown on QF are 2701 miles (which is at the low end of the 2701-5000 mi bracket for QF status credits, so I'm being generous to QF). Then you need 14 segments (38K mi) to make QF Silver (cf. AA Gold), and 76K to make QF Gold (cf. AA Platinum). I'd expect to do about 40-45K mi/yr so this means I will always at least have AA Gold and will push AA Platinum, whereas on QF I'll barely make Silver and QF Gold is way out of reach.
- AA Platinum earns 100% bonus miles whereas QF Gold earns 50% bonus (so even if AA give 70% miles for discount economy on QF, so long as I maintain platinum my loss is small - 140% of mileage for AA vs. 150% for QF).
- Better access to lounges than QF
- Ability to upgrade on AA flights

There are other factors that become more relevant at higher mileages, which I've ignored.

Apparently when I take the platinum challenge in the first half of the year, it only lasts me for the current membership year, i.e. until 3/2004. So I'd still have to get 50K mi this year to keep Platinum throughout 2004. Thus the challenge really only helps me for a limited time this year - from when I've flown 20K mi until when I've flown 50K mi.

My feeling is that the ultimate answer (QF vs. AA) depends on two things: (a) whether I can make Platinum in AA each year, and (b) what fraction of the miles I fly on QF. If I can't make Platinum on AA, then I'm losing each time I fly QF. If I can keep AA Platinum, then since I'd only ever make QF Silver, the 100% bonus due to status with AA overcomes the 70% discount economy problem, and all the other benefits of AA tip the scales.

Maybe I've answered my own question, or maybe I've overlooked something. Feel free to offer any other observations!


[This message has been edited by jridge (edited 05-05-2003).]