I have been disappointed with my Garmin InReach Messenger since I got it about a year ago, for two reasons.
My main reason for getting it was urgent/emergency comms in the backcountry. I navigate by map, compass and phone GPS (Avenza app and GeoPDFs) these days.
1) I was disappointed to learn that the much touted phone app will not connect to my phone without wifi/data service. I put my phone on airplane mode in the backcountry as this vastly improves battery life, and I use my phone most as a camera, and as a back-up navigation aid after map/compass (frankly, aerial imagery on my phone really makes finding inlet/outlet streams in confusing marshy areas much easier than trial-and-error). Once I hit airplane mode, even if I turn blue-tooth back on, the Garmin app won't reconnet to the Garmin. Heaven forbid you want to turn your phone off or need to restart it in the backcountry. I can't imagine why Garmin programmers thought this was an acceptable arrangement.
2) Last weekend I did a two-night trip in the St Regis/Floodwood area of the ADKs. Cell service was very spotty (Verizon/Galaxy S10) but I got a few SMS messages sent and received standing on particular rocks or in certain spots in Long Pond. I was trying to keep up with a family situation at home that arose after I left, and I was debating ending the trip early (family is fine now). I tried sending two custom messages (a huge pain to type out on the Garmin without the app) to my wife; neither sent, nor was there indication of whether they'd sent or not. They still show in our message history both on my Garmin online account and in the device, but she never got them. While attempting to send, I had the device out and held level. I left it out for a while, and refreshed the 'check for messages' function several times. I was on the edge of Long Pond and Slang Pond respectively for the message attempts. Canopy cover was probably less than 50% (being zero over the lake, and reasonably dense on shore). At the beginning and end of the trip, check-in presets did send to her successfully.
Today I tested the Garmin from the yard and was able to send a custom message to her phone and get one back from her. Canopy cover was minimal in the yard, though I was about 10yrds from the house and we do have trees around the edge of the yard. I'm pretty frustrated that when I really wanted the thing to send and receive messages, it seemed to fail without much indication that it did, or why. Would an SOS really send if I need it? What if I get hurt on a portage under full canopy? My confidence is not inspired.