When I dated an older woman (13 years older), I have to admit it was kind of an arranged thing.
For me, it was a summer fling.
For her, it was a kind of how-stella-got-her-groove-back post divorce fling.
I don't think that all relationships of this age configuration are low key though. I think the younger male is kind of the tell of how serious things are or could be. If he is stable, then I think both people can fall into something happy and functional. If he's not on his feet, I think he will be threatened eventually (possibly?).