I posted this earlier in this thread. One thing I didn’t add was that when you hit SOS on a satelite messenger it has to be processed through a comm center and then at some point they relay the information to SARSAT, on the PLB it goes directly to SARSAT, no chances for delay. They also have a powerful strobe which aids in your recovery on most models. Also 5 year battery! In the advanced world we live in today it really is a no brainer life insurance plan.
Keep in mind that any satellite messenger has a much weaker signal than a PLB 1.7W vs 5w. If you’re in the canopy it makes a huge difference especially if you’re injured. PLB uses Govt satellites with a way more powerful signal as opposed to the iridium/Globalstar satellites used by the messengers, once again less chance of no reception. The messengers are great if you want to text while out of a data area, share maps with I don’t know who because if I’m lost or hurt I’d rather have the rescuers know my exact location vs my wife or buddy 1600 miles away trying to convey that, if you want the most reliable I need help now tool it’s a PLB, and a good one can be had for about $400 and up.