JM.
In Dubai, sailing: 2 good clubs, good conditions, year round sailing with no wet/drysuits.
Golf: Lovely courses but a bit pricey.
Horse riding: Don't know, suspect there's some. I spent a lot of time in Bahrain and you can ride horses there.
And as for Hong Kong. People spitting on you in the streets? The chinese used to spit everywhere, not at white people specificly. But since SARS, spitting in the street is illegal and carries heavy fines. And as the chinese are generally pretty law abiding, there's no spitting now. Personally, I find the HK Chinese fairly friendly to 'gweilos'.
Dirty, smelly? It's not that clean but not necessarily worse than London these days. The smells are all part of the Hong Kong experience. It's also crowded, noisy, busy, and things happen at a fast pace. As far as I'm concerned it's one of the most exciting places in the world. It can be expensive, but housing has gone down in price (some property values have dropped 70% since the handover) and shop prices don't differ much from those in Europe these days.
One things for sure. The Asian aviation market in Asia is the one that's really going to grow. Whether you are a part of it in China or at the 'crossroads of the new world economy' as Dubai bills itself, jump in!