I would agree with you, Maciamo. I think of reliable as being someone on whom you can count to get things done. For instance, if my car isn't working, I would think of calling someone who is reliable to make sure that he could bring me to work on time (or to pick me up) before I would call someone who is "tayorigai."

However, on the point of young women liking older men, that happens in the U.S. for the reasons of financial stability as well. And women will sometimes choose men who have a stronger financial standing than one whom they love more, just because of the money and security. Although I'm not so sure how proportionate it would be to the Japanese.