We used an iPhone 15 quite a bit on our recent 5-week trip, and are very pleased how satellite texting works. We were able to connect with both IOS and Android phones, and received messages back from both. I am thinking soon phones will supersede devices like our InReach Mini.
First, you need open sky for either device. In a canyon or forest you may have a lot of trouble. Quite a few times in the Pacific Northwest forests I can't get our InReach Mini (not the Mini 2) to find itself on the planet. Probably the phone will have similar trouble. Maybe the Mini 2 connects to more satellites than the Mini, and phones usually connect to all GPS satellites as far as I understand.
When your "ground team" doesn't get the nightly "in camp" message, they can freak out. But there's been several times I could not communicate with either GPS or message satellites. Also, once on the trip the InReach system must have been partly down, because it wasn't sending out our location.
For SOS (emergency) and sending a message, the InReach sends your location. I'm not sure the iPhone does that for SOS, but they can guide you on how to use another app built into the phone for determining location. Yes, SOS is a different procedure than texting so maybe they'll know where you are. In order to connect to a satellite, the phone takes a few minutes to find the nearest satellite. Then it guides you on which direction to orient the phone. That's much better than the InReach, which tells you nothing and sometimes takes a long time to connect, even with open sky. I'm guessing for SOS that either will work similarly.
For both all communication is by "texting". There is no voice capability. New InReach devices can send photos so maybe they are trying to compete better with the new phones. The InReach always sends your lat/long coordinates when you send a text. For the phone you'd have to write your location into your message. For now, the InReach is slightly better since it sends your location.
The InReach can send messages as text, to an email address, or to another InReach device. The phone can only send a text. Another minor plus for InReach.
We asked our friend for a weather forecast using the phone, which worked well. He's an experienced backcountry traveler and knows how to deliver us a good forecast. The InReach now has "Premium" weather from your location (or a stored location) as one of the 50 messages included in our plan. We used that a lot in Death Valley the past month. If you have a knowledgeable person, it's a tie, otherwise the InReach is currently better.
The phone is generally easier to use with better software. The InReach works more easily with the phone app than directly with the device, but having used it thousands of times that's not an issue for me. But my wife doesn't use it as often and found the phone texting much easier. So the phone is slightly better but you need to practice either one.
Probably as a beginner in satellite communication, I'd start with the phone. Just protect it from damage and bring extra battery energy when away from your vehicle.
Currently, Apple isn't charging for satellite texting. Our InReach plan is about $15/month, plus the cost of the device is several hundred dollars. Certainly using a phone you already have is attractive for that reason. For iPhones, it has to be iPhone 14 or later. I suspect they will start charging at some point. So the phone is cheaper for now.
Many people want to get away from being contacted out in the boonies, but we enjoyed being able to alert loved ones, and get weather and road reports. To each their own!
Hope this covers various cases... ask away if not!
ski3pin.blogspot.com
