Hi,

Neurologist and Neurosurgeons both treat the conditions related to nervous system. The difference lie in the practice of surgery as neurologist does not perform surgery. A doctors profession is a Devine profession. The routine is also busy for a doctor. But if he like his job and do it with a sense of servicing people definitely his soul find relief and satisfaction.

Though I don't have any survey or case study  data in my knowledge  about this fact of happiness but in my opinion the happiness is an internal matter of an individual. So if one is satisfied with his job he would be happy with it where ever he live.If not the job becomes a tiresome task for individual.

If you are looking happiness as a matter of wealth then whatever is your specialization how skillful you are determine your rate of success.

Hops this helps.