Celestar -- I agree with you on elite qualification for CX but for QF "it depends". AA Gold/Platinum is easier to attain on AA than the equivalents on QF (because AA base it purely on miles). However, QF Gold is far easier to attain than AA Executive Platinum
IF most of your travel is in first/business. For something to do (yep, I was real bored at the time), I looked at my travel patterns for the year and compared when I would have qualified or requalified in the top tiers of AA, BA & QF. BA came first by 10 flights, QF second by 5 then AA. Caveat -- all of my flights at that point were in Business or First. What good would it do to have a QF FF account? Well, if onefreeman is going to do a lot of travel to Australia then he may find it easier to get award tickets which are within Asia-Pac as opposed to trying to get them with AA (I'm sure there are lot's of places you want to check out downunder onefreeman, right?

).
tummyg raises an interesting point regarding CP's program. It seems to be the easiest of all to get top-tier in, and even less rigourous for requalification. The added bonus is BA transatlantic flights are eligible for mileage and status accural. So maybe CP is the way to go????