If the wife is happy, you're 95% of the way 'home' in the contentment stakes. Unfortunately, the opposite also applies.
Purely a personal observation, but the happiest with life in the Sandpit appear to be those who've come here from the UK. It's a generalisation - (there are many, many very happy people from countries other than the UK, and there are Brits who are hugely unhappy and all degrees in between happy and unhappy) - but the Brits seem to find the Sandpit more palatable than most. My guess would be that the weather back home has something to do with it.
If you're lucky enough to make good friends - and most importantly, if the wife is willing to get out and get involved in activities and make friends - it can be a very pleasant place - unless you're stuck in unsuitable accommodation, which unfortunately, many newcomers are. (If the wife is going to stay at home and not try to get herself involved in something, in 99.9% of cases, no one's going to come seeking her out, so she'll probably be very unhappy.)
Most (but not all) people are more or less tribal - unconsciously seeking their comfort zone, and people from a similar background and shared experiences. So nationalities tend to gravitate towards their own or another nationality somewhat similar.
But there are a significant number of exceptions, particularly if you (or more often, your wife, because she's here a lot more often that you will be) get involved in some social activity that crosses your particular 'ghetto wall' (my phrase, perhaps a little strong) that most nationalities impose upon themselves, it can be really rewarding to mix with a wide range of people and find that most people are pretty much the same, (and rather nice), whatever their nationality or religion (a bigger factor in this part of the world than in the West).
If your accommodation is in a large compound where every neigbour is an EK pilot, some find it a little uncomfortable never being able to escape 'work talk'. However, some love these large compounds, as the kids have a safe environment with lots of playmates close at hand.