I live in KSA with family. My son was born here, now 12. We are happy here. Well, of course happeness is a very relative notion. First, it depends what place you compare with this place. Then, what is your personal situation. You won't leave Lufthanza for Saudia. But you will come at short notice if you don't have any perspective for job at all. All the rest is in between.
I came when I was desperate and the first three years I would start reading Flight International from the last page (jobs). I couldn't beleive I would stay forever. Now it's 14 years and I don't want to start all over again.
Majority of long staying expats here have been through the same development. And after 10 years almost everybody stays until retirement. You have better benefits and growing final exit money.
Of course aircraft type is important. A320 is terrible, although they are making good money. 777 and 747 are the best. 330 is getting better with new aircraft and destinations. It depends...
There is fear that with new duty and rest regulations they will have to eat into 5 consecutive days off. This will make huge difference if happens.
Regarding lifestyle, it's all up to you. If you want, you'll have everything. Family wise - also depends on family. Mine is fine.