AA Platinum is the same status as QF Gold, giving you QC access (as well as all OW business lounges) while traveling on any OW airline. But if you have already paid for a QC membership what is the value of that? QF won't suspend or refund your QC fee just because you are now AA Plat and can get in that way. So it is a somewhat useless benefit. The real question is whether you can make good use of the miles in Aadvantage. You'll have about 40K miles which is enough for a free ticket on some routes but not enough for the better awards (see http://www.aa.com for details). If these are orphaned miles (you won't accumulate more into AA) it may not be as useful to you as QF miles. In general AA miles are worth about 1.5 QF miles (a legacy of QF being kilometre based and taking advantage of that when switching to OW miles) so you are right in thinking that AA would be more valuable. But only if you earn enough to redeem the award you want. The rules changed this year for coach RTW to make it far less attractive for earning mileage; it is rather complicated and the rules are different in each plan and for each OW carrier (you'll have to research it as I haven't done so, since I will never buy a coach RTW -- not really competitive with consolidator tickets though those generally don't earn mileage).