BD
I am finding clients happy with SQ EK and particularly happy with MH. VS also gets a very good rap. QF/BA are tolerated by those with OneWorld memberships for that very reason.
Korean sneaks in with very good reports, but connections over Incheon suck badly at times and Thai is also popular. There are some very good combination TG/LH J class fares into Europe albeit with an extra stop on the way. If you are a high up QF fractured flyer then you are more likely to get an upgrade on CX if it is full down the back than even their own Asia Miles members. Just a little marketing ploy to gain your future business.
Avoid anything Mainland Chinese lest you get a fortune cookie that states "That wasn't chicken!"
Your agent should be seat allocating you, but before you do so check out seatguru.com - a very handy resource. Most major carriers are listed as are most aeroplane types they operate. The seat rating system is dirt easy to use.
Just don't tell your agent about it. Official Secrets Act and all that!!!!
Best regards
EWL