The actual aircraft you fly is the least important thing ... the whole money / work / life / family balance is what matters.
If the NG was for a *cough cough* rapidly expanding Dubai based lo-co for example, that worked you to the bone and made you do subcontinent night turnarounds 6 nights in a row with min rest in between ... and the 767 was located in some place with a sustainable roster pattern where you could get to some nice destinations and weren't a shattered wreck on your days off, then I would say no contest mate
A lot of people, including myself, came to the sandpit being all star struck by the money and the nice new type rating and the promised "cosmopolitan lifestyle", and got a very rude shock when we discovered how severe the workload was, what a dull flea pit the town was, and how badly it affected the other areas of our lives such as family.