What can you tell me about Sydney, Hong Kong and San Francisco?

I enjoyed Vancouver, Canada. Beautiful Scenery, Parks, wide diversity of people and cultures and a good climate.
So what about visiting these cities? what are the pros and cons?

Never been to Hong Kong or Sydney, but San Francisco and Vancouver are easy to compare. San Francisco is more charming, dirtied, has louder bums, the cabs are more expensive and the beer is usually worse. However, it is so unique in it’s combination of subcultures, architecture, bums, points of interest and just general people that it’s something you have to see at least once in your life. No other major city I’ve ever been in (alright, here’s the list of major cities I’ve been in for reference: San Francisco, Los Angeles, Denver, Santa Fe, Las Vegas, Vancouver, Moscow, Tokyo, Talinn, Salt Lake City, Anchorage, Portland and Seattle) is as charming as San Francisco.