If you get knocked out the inflatables are useless. The auto ones will deploy on a cat due to the amount of spray and a manual won't do a thing when your bell got rung. To me they are WAY less safe than a CE approved vest, yet they are deemed CG certified and if I recall the logic was they are more comfortable and users are more likely to wear them. Exactly the same argument FOR a CE approved vest.
With all your gear on I doubt you would float face up with a regular PFD anyway (lots of rear flotation in the harness)...so if you're unconscious, you still have a problem...though at least you have a better chance at being near the surface.
