R2000/1830
You have asked a deeply probing question. It comes down to what we individually determine is happiness.
There is happiness at home, in the 'office', with career development etc. It is not appropriate to have a simplistic answer to such a question as "are you happy". Viktor Frankl found some sense of happiness in the most dire of circumstances in a nazi concentration camp...now I don't wish to suggest that things are that dire here at CX. Merely that some will find happiness no matter what the circumstances.
Maybe a better question would have been - "are you happy with how you are treated as a professional aviator at CX?" That might arouse more informational responses than a simple yes or no.
Expect to just be a 'cog' in the machine whilst here - nothing more and nothing less. That is the treatment from a corporate viewpoint. The actual coal face is far more personal and responsive - I would suggest that on the whole most guys are happy at the coal face. They are not happy with the professional aspect....upgrade 'hoops', moving goalposts for time to command, lack of corporate response to a deteriorating remunerative environment etc etc.
Happy with life - yes! Happy at the coal face - yes! Happy with how we are treated as professional aviators -?????? Not sure it is much different at other airlines...mates of mine in EK/QF seem to think things are bad all round.
If you don't have any equal or better options, take CX! You can always move on later...