My main route the past year and a half is London-Australia/NZ in business roughly every 3 months and so I've done quite a few options beyond CW, including CX, QR, QF, TG, SQ, NZ, VS/NZ as well as mixed AY/BA, OS/TG, LX/QF or CX.
CW is not the best, but it is definitely not the worst. QF A380 "flat" Skybeds, TG's angle lie flat seats on 747s and 777s (and the grim lounges at BKK) and the very mixed service on QR all rank below CW. CX seats and lounges are better, but on board catering is poor recently. SQ is generally excellent, but I much prefer the BA and QF lounges at SIN over the tired crowded Silver Kris lounges. NZ is good too, but to go all the way means LAX transit and it is generally pricey.
CW is ok, its strength is consistency, its weakness is hard product that means many seats are undesirable (aisle seats are very exposed, middle seats are too close to others except upper deck A380), and storage is poor. I can sleep in CW which is the main point in my view. Working is ok, but basically I choose on price. I have a limit in budget for long haul business on this route (sometimes it means going ex.EU) so I go CW if it is competitive. However, I'll generally make the trade-off on price and schedule, and if I can't get seats 16A/K on LHR-SYD on 777s, then I'll probably not bother.