Just done my first ever J trip on QR - LHR to BLR.
Economics defined the choice - how can J in QR be cheaper than PE on BA (my normal travel level for LH) although I am not complaining?
i was pretty impressed by QR although underwhelmed by both lounges compared to the First Lounge at T5. Doha one at least provided decent aerobic value as I tried to find somewhere interesting to sit.
For me QR hard product with a decent BA crew - flying heaven!
Sadly I suspect a marriage that I may not see in my travelling lifetime.