After 50. Is Shacking up, living together, and marriage worth it?

There seems to be little discussion of the late bloomers starting unions and marriages after the age of 50.  As a couples counselor and marriage therapist in the Los Angeles and Beverly Hills area I do not hear about the aging process among the happily elder couple. With magazines and Film industry’s emphasis on youth is there a place for the aging in love? The individuals that joined the marital wedding party upon their own invitation vs. crashing into a disastrous union might have merit.  Who are the people who just married late or who found good matches late in the game?  Are there any thoughts other than “going down to city hall" in middle age?