The device does appear to have a dedicated SOS button meaning that in an emergency it can be used without connectivity to a cell phone. To me, this feature is very important for several reasons. Most importantly, the device itself can be triggered without navigating a touch screen, which can be difficult to do in cold and wet weather with gloved hands. In the event of a fall or other emergency, having the device right on my shoulder strap makes it more likely that I'll be able to trigger an SOS. Also, having used touch screens in cold and wet weather, I wouldn't want to have to go through that process in a true emergency.
I have an older InReach which has a screen and can be used without connecting to a phone (which is how I use it to send messages), but it is relatively bulky and expensive so I do not keep it active normally, only when I go to the Sierra Nevada. For hikes on the Appalachian Trail that are more local, I just carry a cell phone and connectivity is spotty when not on ridges with sightline to populated areas. If a $99 device costing $5/month really works, I would be willing to just keep it active year round offering some additional protection. I'll wait and see what initial reviews in the field have to say.
ravi_jmt2013