This does work for someone like me. I have been Platinum for at least the last 10 years, but never get to EXP because my travel is spread around to many locations on many airlines. [This year, I might not hit 50K on AA without codeshares because although I've done 6 BOS-LHR trips so far this year, the client for 5 of these has a deal with BA, but since I'm a 2 MM miler, I'm OK]. However, I'm virtually certain to do 2 more business class trips to Europe and one trip to Sydney.
As long as using this card as the payment vehicle didn't preclude reimbursement by clients, I'd get EXP for part of the year in return for the foregone interest on $10K for a few months. Is the differential between Platinum and EXP worth $250 pre-tax (5% on $10K for 6 months)?