Perhaps not unimportant, also investigate what maintenance/ testing costs of the PFD will be. Some are either hugely expensive to test and for some are spares difficult to get. Generally there are only a few manufacturers of the actual actuating device (Halkey-Roberts, United Moulders) and make sure it is this kind of general and not exotic brand. If you are frequently sailing in poor and very wet conditions, you could consider a “Hammar” actuating device. (As your saltpill actuator may inflate in severe conditions, especially on bow conditions)
Also go for sufficient floatation, like 275N, which will be capable to turn your head above water when you enter it unconscious and prevents you from immediate drowning..