Anecdotal evidence: although sympathetic to the idea, I am not signed up, and have had two close brushes with death (that I know of).

Not in my case for the original plan. I decided to sign up for cryonic suspension some day at age 14 (1974), after reading Robert Ettinger's Man Into Superman (an underappreciated book, in my opinion). I followed through in 1990 with Alcor. This November 2 (coincidentally my 51st birthday) marks the 20th anniversary of my suspension membership.

I did have an health issue recently which has motivated me to get more involved in trying to untangle the cryonics clusterfuck (long story). I had a branch retinal vein occlusion in my right eye back in June (basically a stroke in that retina), which has caused some vision loss. Since then I've lost about 40 lbs. and I take Lisinopril to lower my blood pressure (116/80 this morning).

I've had a fair number of relatives die. This is actually one reason I'm delaying on cryonics right now. I first got strongly interested in cryonics about 6 months ago. Then shortly after that, multiple relatives of fairly young ages died fairly suddenly. They weren't the first such deaths in my family by any means. And a family friend died at about the same time from cancer that he had had for a very long time. The initial reaction was that I should run off and sign up for cryonics right now. So I'm now delaying in part to make sure that I am making the decision more rationally and not just based on sudden recent events clouding my judgment. That and the whole thing with cryonics being fairly expensive for a grad student budget are the main causes of not signing up at this point.