Good Question.
The single biggest issue in my opinion is the combined question of how long do i think i want to stay, and how am i going to escape when the time comes. For me, I only want to do around 10 years here, but i need a job to leave. At the moment there are no jobs. Will there be any in the future? Who knows. If there are, will they pay enough? Who knows. Will I be able to leave after 10 years? Who knows. One thing is sure though. If you have kids, it is unlikely you will have saved/invested enough to retire after 10 years. The provident fund will only provide a robust deposit for a house in that time.
The other big issue for me (and most of my compatriots) is that we do not want our children spending their high school years in Dubai. I am not going to go into the reasons for this, but they are many and varied. So my plan is that my kids will go home for high school. That leaves my wife and i with a difficult decision. Do we send them to board and essentially lose them? Do we send the wife home with them and I commute? (far from ideal). Or do i just chuck it in and hope something comes up?
The job here is good, and life is fun and easy. But it is not a place where most people want to stay until they are 60. If you can realistically see a way around this, or you think you will be happy to stay here until you are 50 or 60, then come on down. If you are not sure, you may well be better off staying put and reaping the benefits of staying at home. It is fair to say that many people love the life here and have no intention of leaving. It is also true that many people are separated from their families, spending a lot of time travelling, generally hate the circumstance that they find themselves in, but are unable to leave due to the golden handcuffs that you can find yourself in after 10 years with Emirates. Good luck