"A PLB is the better choice if you don't have loved ones that care where you are, how you are doing, and won't get in a rush to find your body."
If I wanted to be as inflammatory, I'd say, "A SPOT is a better choice if your loved ones (1) want you on a short leash or (2) your loved ones are better at performing SAR then the Coast Guard, Civil Air Patrol, Sheriff's Rescue Squad and the National Guard. But absolutely, for some, SPOT is a better fit and worth the added costs.
For me, at my lattitude, and in rough terrain, the better reception of some PLBs trumps SPOT's other capabilities.
The SPOT "Help" button is, in my mind, more useful than the "okay" button. (although, each, obviously, only means what you tell your phone/email list it means). The thing is, it is hard to compose those one or two help messages in advance. I do know pilots who have good contingency plans in place (and often are utilizing the tracking function), but mostly I think of the "help" button as the "send beer" button.