Unfortunately EXP seems to have a certain reputation (at least with AY and IB) and gets ignored a bit, while QF Platinum has more clout (more than BA Premier, rather perversely -- don't ask how I know this). Mostly a case of rarity, plus AY staff know of some marketing ventures with QF, so they react to seing QF Emeralds. In any case several times I've had trouble making some simple booking changes, and EXP was getting me nowhere, but flashing QF Plat brought a quick call for a supervisor and things suddenly became a lot smoother. Part of the strange world of Oneworld. But it is certainly true that many flights will have a single Emerald on the plane (vs. other routes, such as QF SYD-LAX, that has dozens of Emeralds on every flight).