It's amazing how there are uses that don't cleanly define what's best.
Most of the time we will use self inflators. They tend to be the nicest to be wearing on a hot day and if either myself or one of my children end up in the drink it wouldn't be by design so having the buoyancy automatically deploy is sensible.
But then, the children often want to go swimming or mucking about by the shore!
For swimming I favour the cheapie, orange jackets. Bulky, intrusive but in the sea they will keep the child right way up and afloat all day so they win out over buoyancy jackets.
For mucking about along the shore, up rivers or on paddle craft the buoyancy jackets make the most sense, less obtrusive and help keep them warm etc.
So, in short, buy at least 3 different types for each person and fit a wardrobe to the foredeck.
I get by with self inflators all round and cheapie, orange foam jobs for everything else.