I like my InReach SE. I like being able to two-way communicate out where there's absolutely no cell service.
I've found the following:
-It takes a while for the first message to send. Like it almost needs to "warm up" i.e. establish the satellite connection, so the first message seems to take a long time to go through. Subsequent messages after that seem to go much more quickly though. Also, I've noticed shorter messages send quicker. Sometimes I just send acronyms to my wife to check in with her because it's quicker to type and sends quicker as well.
-It would not send one under thick tree cover. So if you're in dense bushwhack territory, you better find some type of opening otherwise I think you'll be out of luck. That was my experience anyways.
Question: Do Satellite phones work when it's snowing or extreme fog and cloud cover? Haven't tried that yet.