This is just my opinion, but I'm a fan of phones over devices. These days they're smaller, lighter, and easier to carry in front pockets/pouches. if you're worried about batteries a small charger is still smaller and lighter than most GPS's are and still much cheaper. And nearly all of the mapping apps like OnX have exactly the same data for phone and device... but again, cheaper.
I also like having some options for mapping apps. GPS's are really primitive. Most have screens so low resolution it can be hard to tell which side of a property line you're on without zooming in all the time. And while I love OnX for what it does, it's actually a pretty crappy mapping app. Locus Pro is much more sophisticated - I can swap out USFS Topos with motor vehicle use maps (access is important in Colorado!), record exactly where I find sign and bedding areas while scouting, etc. A GPS can do a lot, but a phone app almost always does it better. Being able to record location markers with photos is my biggest selling point.
There's nothing wrong with a physical GPS. It's super subjective and I totally respect people that prefer them. Ruggedness is the usual selling factor: they're way less fragile than phones. I just really like Locus Pro. It fits me. So I use a phone.
On the other hand I do NOT get that "no cell phone at all" thing. I don't know the laws in Montana but here in CO hunters have all kinds of legal obligations that require phones to support. If an injured deer runs over the border of a private parcel you're required to call the landowner, and if they won't answer, call the CPW. You can't knock on a door and ask to use a phone because EVERY property has "no trespassing" signs up, and usually locked gates too. If my buddy is hurt, I want to call 911 as fast as I can hike->drive somewhere with signal. Yes, I usually have no signal where I hunt. But I also usually get it back way before I get to a town. That time could be life or death.
With all due respect, I also don't think "this guy had a cell phone and trespassed on me" is a great argument, if you're really objective. OnX is the same data on a phone as it is on a GPS, and printed maps are often unreliable with respect to trespass concerns because they're usually only updated every few years. If they couldn't be bothered to use their app properly, no Garmin is going to fix that for them. They had every tool needed to avoid trespass and still did it. They're just morons, and you can't buy solutions for THAT.
PS - Don't mix "cell phone service" with "GPS functionality". You don't need service to use the GPS and maps in your phone. I have the whole state of Colorado downloaded for offline use. I almost never have signal where I hike and hunt, but I still prefer my phone. Works great.
