My speculation is that QF pays between 5% and 8% commission, and CX pays slightly more. At least this is my observation from TA behaviour. QF service is excellent if you have status with them, otherwise it can be slow without QF status. One advantage for tickets issued by QF is that it is in Amadeus, so you can use http://www.checkmytrips.com for all the legs of your OWE ticket.