As I'm also a little paranoid, when I test my auto-infatable vest next time, I'll also test using its manual inflation tube. If the auto-inflate mechanism fails (rare if the pill is not expired), next I'd try its manual inflation pull cord, and if that still didn't work, it'd blow it up using the manual inflation tube.
I think you eliminate the most risk by going with which ever PFD you'd actaully wear, whatever your preferences are. I've read in many places that most marine deaths by far are due to no PFD at all.
The new Spinlock auto-inflatable Deckvests seem to be enginered to take into account a broad range of the previously mentioned concerns (although no one product will address every worst case scenario), but they're not cheap. They are very strong, light weight, and have lots of features. Some might prefer a simpler approach though.
Welcome to the Spinlock Website
The Deckvest is the latest evolution of Spinlock's award winning harness and lifejacket technology
Features and BenefitsNew Deckvest model approved to ISO12402-3; the new International standard for lifejackets and ISO12401 for Deck Safety Harnesses
Compact 3D Shape, with front opening belt system for fast and secure fitting every time
Wide range of chest and back adjustment for perfect tailored fit
Soft loop harness attachment point
High Spec Auto Inflating 150N Lifejacket, fitted with sprayhood
UML Pro-Sensor activation head with visible indicator to show activation status
Aquaspec AQ98 high intensity flashing light
'Manual Only' firing head supplied to order
Available in 3 sizes