I will start from the happiest pair
1. American guy married to a Canadian lady that is 9 years older than him with no kids. They both have high income and they have common interest too. Their marriage is very happy. I honestly could not tell the lady is that much older than him
2 Canaidan guy married to a Chinese lady who is 9 years older with no kids. That Canadian guy behaves like a spoiled child. He is the main source of income of the family but spends money like water. I have no idea how he maintains his life style. He is very high maintenance. But overall they are still happy.
3. American guy married to a Chinese lady who is 9 years older with two kids. The American guy is in between of jobs periodically. The Chinese lady did well professionally. I know the guy. He said his wife cries all the time and every time when she cries she would say how much she regret to marry to a guy much younger. She thinks finance is way more important.
4. Chinese guy married to Chinese lady who is 8 years older with kids. I have no idea on this pair as we lost in touch
5. American guy is living with a Chinese lady who is 12 years older. The Chinese lady is very wealthy so pretty much she supports him on everything.