My opinion was that Larkin had panache. He wasn't conventionally sexy, and it stretched the imagination that young women like Roxie and Mindy would physically attracted to him, but his appeal was evident. As I recall, Larkin was hit by car at the height of his initial success on Edge of Night. When he returned he was noticeably more gaunt, but he still played shirtless sex scenes.
It was also an era when east coast actors were not all as ripped and toned as actors today. And, a slightly older guy could still be cast as a single leading man without many questions. For example, Michael Wilding Jr who played Jackson Freemont had some of the sharpest cheekbones in the biz, but he wasn't a chiseled hunk, and Warren Burton who played Warren Andrews got by on his charms, without the visible attributes that would indicate he was attractive to gals like India.
slightly older Larkin
I am probably preaching to the choir, but, while I appreciate the idea of tying Sally and Donna's secrets together in the Royal Dunning/Emily Benson mystery, given Sally's rebellious youth, the retcon of David Thatcher and Kevin were totally unnecessary. Sally could have been pregnant by Phil, Leigh, Denny, or Joey and had consulted with Dr. Dunning off screen. But, I guess, that would have left us without a murder victim.
I like a murder mystery as a backdrop to a burgeoning romance, but as much as you disliked Brittney, I found Kevin to be one of the most obnoxious children in the history of soaps (coming a close second to GH's Mike Webber)