I lived in Dubai for 3 years and Oman for 6 years before that and moving to Hong Kong was the best thing I ever did!
Saying that, if I'd been here for the same amount of time I'd probably enjoy being in Dubai.
You may not have income tax but you'll find that living in Dubai doesn't mean you'll automatically save 15% every year. Accommodation is just as expensive, you'll have to buy a car and a lot of the things you take for granted here are not there. Yes, you have beaches which are clean, but during the summer it gets up to, and accasionally over, 50C with high humidity so you'll find that you are inside most of the time or in malls or restaurants spending money.
If you are an outdoors person it is a great place as the diving, camping etc is really good in the months when it is possible.
There is a lot of drinking going on there and although there isn't a Lan Kwai Fong, there are a lot of places where you can actually get to the bar on a Friday night and get a drink.
Although a Muslim country it is very accepting of other nationalities and cultures, you just have to show some respect to your hosts, as with any country.
If it is for 6 months I would say go for it, but only if the package is very good. Don't go there on your HK salary and expect to come back with savings- especially over such a short period.
As far as 'Asians' go KnowItAll lives up to his name. The Indian/Pakistani population far outweighs the population of any other culture there, I think they represent around 70% and are found in many areas from exceptionally rich entrepreneurs to taxi drivers and construction. There is also a large number of Phillippina and Malaysians there as they are often Muslim too and look after homes and children.
I'll help if I can with anything else. i have a friend who runs a business there- Explorer Publishing- and they have a website at www.the-explorer.com, it may be worth ordering a copy of Dubai Explorer to give yourself an idea.