Scott, I was a dedicated Delorme GPS user (really like their maps) until I got the Montana. Reason? The Montana has a connection for an external antenna. My home away from home is a 4x4 windowless van and no GPS I've tried gets a signal inside there unless there is an antenna on the roof. Now, with the Montana connected to a good Gilsson on the roof satellite reception is no longer a problem. How do you hook an external antenna to an iphone??
Also, and bear with me because I'm an old dog trying to learn new tricks. I don't know much about iphones and such because where I live cell phone reception is at best spotty and a lot of the time nonexistent. Same with internet. I spend a lot of time in back country where there are only two-tracks running in all directions through the brush, no road signs of any sort and certainly no addresses. But I have been able to find maps for the Garmin that give a name to every windmill, spring, abandoned mine, canyon, etc., out there in the middle of nowhere and still give me the topographic information I need so I can locate myself exactly on paper maps. I have these same maps loaded on my computer at home, and I create tracks taking me to places I want to explore and load those onto the Montana. Following that pink line has saved me from a lot of stumbling around on dead-end roads that went nowhere and I sure wish I had this tool many years ago when I was younger. Are you telling me I can do exactly the same with an iphone?