i've had very mixed experiences. Usually not a problem starting trip in SE Asia, BUT ALWAYS a problem when starting trip in N America and Europe. Have to argue EACH and EVERY time. They always do it in the end, but not a great way to start a trip. Check in agent always says no, they I ask for a supervisor (Actual QR employee). Results are mixed. Some relent, some continue to fight. Show website. Sways some, no others. If still battling, ask them to call Doha. I don't know who they call but it works.
I know keep an email from QR on my phone (from customer service) stating they do in fact check thru on separate tickets. Haven't had to show it yet.
Agree with others. For such a great product in the air, the ground is horrible. Their call center is even worse.