Been using my InReach for four years. Wouldn't go offshore on anyone's boat without an InReach. A couple of neat features:
1. On my boat it communicates fine from inside the cabin through the deck. While this would depend on your deck structure, others have told me this works for them too. So my InReach just sits on the chart table turned on and pugged in. Family know they can reach me anytime - so they worry less. Better, you can set the InReach to beep continuously if a new message arrives. This saves you from constantly checking the thing.
2. While I still have an EPIRB they are 40 year old technology. Amazing in the 1970's. I would use the InReach first in a distress situation because: a) I'll get a response so know that my message got through b) In a difficult but not yet life threatening situation, I can ask SAR to keep regular contact. With an EPIRB your only option is a full on "MAYDAY" which may not be what you need.
Here's a good video from Garmin: