After several years spending over $300 a year renting sat phones, I finally picked one up. I wish i did it sooner. The iridium network covers all of north america and this device will still allow you to communicate in overcast conditions (iridium sat phones are an exercise in patience during anything except ultra clear conditions). Preset messages are included in the basic plan at no extra costs so its easy to send a simple safe at camp text each night. You can also set it up to include a link to your position within each text.
We set ours to send a location point to my Garmin account every hour. That way if you fall, are attacked by a bear, etc. and cannot hit the SOS, they will still be able to find your vicinity. Also, my wife can check the account and if she hasn't received a safe at camp message for 48 hours and my location hasn't moved, she can call in my location. It's also fun to track your daily progress once the trip is over. The mapping leaves something to desire, but it's an emergency device designed to find way points for camp and water; not strategically pick apart a topo map to find a hiking path.
I don't like that it doesn't have an interchangeable battery. But, there are lightweight battery packs that will charge the device and a phone if you're on a short trip (3-5 days). A solar panel is necessary if you use it for longer than that. One battery will last about 10 days if you shut it off the majority of the day (no tracking) and only use it to maybe set a couple way points and send a text a day. If you only want to use it for texting and SOS, there is now a mini. I don't know anything in regards to the battery life on that thing but I know a couple guys that have already returned theirs and gone back to the explorer.
My buddy used the inreach on a hunt in the Wrangell's where I had a sat phone and he had constant contact while the sat phone only worked maybe 50% of the time. We had all types of weather on a 7 day hunt on Kodiak in February and the inreach worked flawless at all times. I believe in the device enough that I will be trusting it with my life in the northern Brooks for 16 days in two weeks. And that's about as remote as you can possibly get in the U.S.
To summarize: buy it!