The service on CX is great but very crew-dependent but from what I've read KE is at least on par with CX. Throw in the fact that you get a new suite on a new plane on KE (CX's F hard product is now 5 or 6 years old) and again from what I've read in other people's TR, better food and drinks (CX F catering really is rather J-like), even though I am a CX fan, I think the KE would be a better use of miles and time.