There was an interesting article in the print edition of The Times today. It may be on the website but, as I don't subscribe, I don't know. Quick sum-up.
1. The article claims that QA will more or less break even on the route if business class and freight are full. Economy passengers are profit. They envisage freight Cardiff>Qatar will be fully loaded because of fresh lamb exports.
2. Cardiff is preferable to Bristol for long haul in QA view because it has a greater captive catchment area. Bristol would be competing more with Heathrow and Brum for long haul passengers. I find this interesting as for short haul it's always claimed that Bristol has the larger catchment. I guess it's a sign that the two markets are very different - hence the Welsh Government's eagerness to set APD for long haul services
3. 'Rumours' that QA want to use Cardiff as a hub for North American destinations and may want to buy a 50% share of the airport.