So far we have only sailed our 39' boat on Puget Sound. The rule on boat is... if we need to reef everyone wears one. We are thinking of changing that to everyone all the time, but when its sunny and 80 degrees with 6 knots of breeze and half foot wind waves it seems a bit silly.
When we drop sail near the marina, we are near ferry, freighter, tug traffic and their wakes. If someone goes forward to adjust the lazy jacks they wear an inflatable pfd with harness rings, with tether available if they desire.
No body has brought up the scary subject, what if the inflatable doesn't inflate? A lot of faith seems to be put in these devices, myself included. Yet there is a poster here who won't allow them on his race boat for having seen them not inflate. Just a thought.