I wanted one that automatically inflated but was comfortable to wear all day, and was buoyant enough for me in my winter fishing gear. I weight 265 and in the above video I had just got back from fishing so I had my heavy winter fishing jacket, thermal underwear, insulated pants, sweater, heavy duty boots and hat on.
It worked fantastic. I also found out a few things. There is no way in hell I could get out of the water and into my boat without some sort of ladder. You can see me trying to get out of the pool not using the ladder and it wasn't even close. I weighed probably 60 pounds more when I got out due to the water logged clothing and the bulk of the inflated PFD made getting close to the pool edge impossible.
I also found out that swimming forward was very hard and it was much easier to do the back-stroke.
As you can see it took about 1.5 seconds for the auto inflater to kick in, but it did deploy and had no problem keeping my head out of the water.
You must be wearing this in order for the Coast Guard to consider it a viable PFD, but is honestly so comfortable I forget I was wearing it.
Sorry about the sideways video.