Orangputi-Yes, pollution is bad in HK and is getting worse. However, I always found HK to be a more interesting place to live, it's not as stale or boring as Singapore can be. HongKongers are a rude lot, but they are not as inflexible and rigid in their thinking as Singaporeans are...which can be a good or bad thing depending on one's circumstances. So Hong Kong is a far more "interesting" place to live!
bartholomewrose-Good point. Although since SQ is owned indirectly by the Singaporean government..so SQ is backed by the power of the state...if I recalled, the the Singaporean gov has directly intervened in several occassions to mediate. Their unions however were far more divided and split by internal divisions, politics and feuding...although both the union and sia now states that their relations are more cordial both within their organization and between them...or so they claim.
But in other more general aspects, HK has greater freedoms..at least you won't get arrested for openly criticizing the gov, which you are liable to do in Singapore. Civil liberties are more protected in HK.