Hopefully, folks with "pull-to-inflate" PFD's are regularly popping a
CO2 cartridge to make sure they work....at least 1-2 times per season...*especially* if you're spending any time around salt water. They only have to fail once and you're in trouble. Give me a "solid" PFD any day!!
(the 'yak ones are so well-designed at this point, that you'll hardly notice you've got it on...)