Battery life is about 10 days with minimized settings and an unobstructed view of the sky. I wore it on my pack for a climb of Shuksan, and used about 10%. It also has better satellite connectivity than the Mini1. And it seems very durable in an outside environment. I did not feel like I had to baby it. Just set it and forget it. (I have shattered phone screens in my living room and broken a camera on my first use of it, before I even took it out of my backpack.) and it works with the Garmin messaging app. Text messages from your phone to the M2 are seamless. However the messaging software on the M2 itself is terrible. The software interface for the system settings is also aweful. But you can do a lot of it on your cell phone. You really need a cell phone to get 100% use of the Mini.