nas or china
As far as how the Airline treats you I have had better treatment in China, there is a lot of BS and quasi lying when it comes to NAS. It's a pretty screwed up place, perpetually burning through tons of cash mainly from internal fraud and piss poor business practices. The NAS management is a constant revolving door of mainly SABB bank managers who have no idea what they are doing. I'm sure you guys have read the threads from a year or so ago, all the mud slinging between the western pilot's and the Arab ones, This is a product of the upper management bring in westerners, usually brits, to try to get the operation running like it should. This ultimately leads to them pissing off the rank and file of the Arab pilots and Flt. Ops. types which leads to them running to the Arab upper management whining about how "the foreigners are ruining our company, we should take care of ourselves" so then they clean house, put a bunch of arabs from the region with dubious qualifications to do things like D.O. or Trng. manager and they promptly run it back into the ground.
And as far as lifestyle there is absolutely no comparison, the fact of the matter is unless you are Arab and Muslim you are going to feel really out of place. Do not kid yourself, this is a very different, closed society. I am not making judgments but if you are from the west it is a huge adjustment. Everything closes 5 times a day for prayer, you will never ever see a female in public much less have ANY hope of meeting one unless you live on a compound and the million-to-one chance of a single expat woman lives there (I'll be blunt, that is not going to happen.) There is no alcohol, you might come across home brew if the compound you live on is making their own, but the main thing is there is just nothing to do. Arab society in the Kingdom revolves around family and prayer and little else, and by the way 6 months of the year it is so unbelievably hot you don't want to do anything anyway.
As far as China goes how you are treated by the airline would depend on which airline you fly for, any of you guys want to P.M. me I'll tell you who I fly for and yes I like them just fine. The tough part about China is if your from the states it is truly the far side of the world and on paper, and I emphasis on paper, the Saudi deal is better due to the fact that they give you tickets home and I don't think any Chinese carrier does that. I am full time here but I know plenty of guys who commute and it runs them about a grand on average year round per round trip ticket from where we are.
The tough part of flying in China is mainly dealing with the CAAC. Taking the Chinese written, the lengthy time for all paperwork, licenses, work visa, ramp pass to get processed. The fact that you have to get the circling restriction removed from your license only to find out that they don't do them either! But the worst is the dreaded Chinese medical. I am again not going to sugar coat it, it's tough, it's unreasonable, and change in China is measured by centuries. We all live in constant fear of, fatty liver, gall stones, kidney stones, any thing less than a perfect heart, blood pressure, a weird treadmill stress test, etc. etc. The first medical is nothing short of NASA 1959. Most of these problems they will let you get sorted out but it's just anoying that anywhere else in the world no one would not care about 90% of the crap that here is disqualifying.
The actual flying can have it's challenges. Personally I can understand the Chinese speaking English a lot better than the Arab accent. On the downside, the Chinese speak Chinese to their indigenous crews. Unlike the Middle East which has only 2 kinds of weather, CAVOK or 50 meters in a sand storm, China has a lot of weather but nothing any airline guy from Europe or the US hasn't seen before, but your on your own in dealing with it. Also the Chinese fly using meters, it's a pain in the butt, you carry a little laminated card with the conversions and of course your Chinese F/O loves to constantly show you that he has it memorized and doesn't need a card.
For all that life in China is very good, I brought an American wife and a 10 and 13 year old son with me and they all have had a great time here. The Chinese are a very gracious and gentle group of people and after 18 months in Saudi it was very refreshing to not be in a society so controlled and restricted. Any activity that you may have enjoyed in the west, except for anything involving a firearm, you can do here as well. Nightlife is in abundance as well as a never ending supply of very beautiful Chinese girls who are fascinated by western men.
Sorry for the lengthy thread and I know it fairly broad spectrum but hopefully this answers most of your questions if you leave me an email or skype in a pm I'll do my best to answer anything else more detailed oriented.