It's a wonderfull tool. But:
The first minus is lack of user guide. I'm always not quite sure what it can do, because from time to time I surprisingly discover features of Lunar. I use it from about one year. Just recently I discovered that it can redial last number. Before that, few months ago, I discovered that it can invoke the voice dialing in my phone. So I can suppose, that in few months I will discover the new surprise.
But I rather would like to have the user guide. For instance, after unpacking I found it switched on (while unpacking I must have pressed the button enough long to turn it on, of course only by chance). When the red LED went out I spent about an hour guessing how to turn it on.
The second minus is the extra-large button. It is extra-large in fact, but I'm afraid it will work not very long, because it has stopped to click already, so each time I press it I don't know if it works or not.