What is your opinion of relationships where there is a significant age difference between partners?
A relationship between a 13 year old female and a 23 year old male is, at best, statutory rape (though there are times and places where this is not so). Relations between 23 year old females and 33 year old males are common and unremarkable. A relationship between a 63 year old female and a 73 year old male? Why they are practically the "same age" anyway. (But statistically, the female has a good quarter century ahead of her while the guy is practically at death's door). Notice, though, that in every case i made the guy older. I've never heard of a "trophy husband" although i am sure they exist.
If by a "significant difference" we mean 20 years (assuming both parties are legal adults) we run into the fact that culture is changing very rapidly and people twenty years apart might run into the mixed relationship problem. We still caution people about mixed religion and mixed race relationships, but i think "mixed time" relationships can be more problematic. If she is twenty years older than i we are less likely to share the same view of the world. I would have become adult after World War II, she before, right at the beginning of the great depression. We will likely thing each other's beliefs, perspectives, even behaviors to be odd at best.
In the 19th and early 20th centuries, twenty year differences in the ages of couples were not uncommon and it was almost as common for the wife to be older than the husband. People died young and their mates remarried whoever would be suitable. Is she a good cook and of a maternal nature? Is he a good man and a reliable breadwinner? Time past more slowly, radio was around almost a quarter century before television was even heard of by most people; television was around 12 years before i bought one and i did not feel i was odd or old fashioned. In the 1930s a man or a woman (or two men or two women or three men and two women -- though the rest of us would have known nothing about such arrangements) of different ages would have had much more in common than today.
If you were to ask me should a Moslem and an agnostic have a relationship, or a Nigerian and a Dane? I would say, it depends on the couple and the people they will have to get along with. Its the same with age differences.