Does anyone use belt PFDs?

I suppose it beats nothing in calm, flat water.

But why not a conventional inflatable PFD? Maybe something in a nice navy blue, with a Disney licensed Mickey Mouse design to brighten it up?

Bubblehead-
"I wish I could try one or at least see one inflated before I buy any though. "
When I bought my Crewfit, prior to all the acceptance and regulations, at a boat show they rep said "Here, try it on" and without telling me, he reached up and pulled the inflate tab. Which ain't cheap. But it did make a point, and he sold one to me and one to my friend at the same time, point being made.
If you can't find someone at a show to demo the fanny pack for you, assume that make isn't what you are looking for and see someone who understands marketing & their product better.
(Crewfit has no interest in the US market ay more, and never got USCG certifications, but I keep dancing with the one I came with, so to speak.)
I can always stow it in my daypack, although I've sometimes wondered, if I fall in the water with it stowed that way, htf am I going to get it OUT of the pack again?